• Military Menu                       

• Introduction
• Systems
• Facilities
• Agencies
• Industry
• Operations
• Countries
• Hot Documents
• News
• Reports
• Policy
• Budget
• Congress
• Links

• WMD
• Intelligence
• Homeland Security
• Space

Salpa Line / Salpalinja

The Salpa Line (Finnish: Salpalinja, literally Lock line; Swedish: Salpalinjen), or its official name, Suomen Salpa (Finland's Latch), was built in the 1940s to protect Finland from the Soviet Union. The system of more than 700 field fortifications was made from concrete or excavated from rock along Finland’s eastern border. Stretching 1,200 kilometers (746 miles) from the Gulf of Finland in the south to modern-day Pechengsky, Russia, in the north, Salpalinja consisted of bunkers, trenches, fueling stations, weapons depots, and more. The line incorporated many lakes and marshes into its terrain, as these areas could be tough to navigate and easy to defend. It is the largest construction project ever carried out in Finland during the period of independence, with a maximum of about 35,000 civilians involved in the construction and renovation of about 2,000 lots.

The Winter War between Finland and the Soviet Union took place in 1939–1940. As a result of the war, Finland lost some areas but retained its independence. As a result of the Moscow Peace Treaty that ended the Winter War, Finland lost a large amount of its land area to the Soviet Union. The outer islands of the Gulf of Finland, the Karelian Isthmus, Ladoga Karelia, Kalastajasaarento and parts of Salla – a total of about 12% of Finland's land area were ceded to the Soviet Union. In addition to the loss of territory, Hanko Peninsula had to be leased as a Soviet military base for 30 years. Finland nevertheless managed to maintain its independence, although the country's war leadership did not feel very confident about the permanence of peace. In the Winter War, the Soviet Union had failed to achieve its main objective, which was to conquer the whole country and join the Union of Soviet Republics. In Finland, it was believed that sooner or later the Soviet Union would launch a new war of aggression to complete its conquest expedition, which had been halfway through the Winter War.

As a result of the Peace of Moscow, Finland's new eastern border was located in terrain that was considerably less favourable in terms of defence. The narrow Karelian Isthmus between the Gulf of Finland and Lake Ladoga, for example, had been defended with relatively little military force by relying on rivers flowing on the isthmus, whereas on the new border, reliance on waterways was not possible in the same way. Against this background, the Finnish military command considered it of paramount importance to fortify the new eastern border as quickly and strongly as possible. The Commander-in-Chief of the Army, Marshal C.G.E. Mannerheim, made the decision on the matter after negotiations at the Inkilä Manor near Mikkeli on 22.3.1940 – already nine days after the end of the Winter War. The decision was undoubtedly influenced by the fact that the experiences gained during the Winter War from Finland's main defence position, the Mannerheim Line, were quite positive. A strong fortress had been found to give the defenders considerable advantages in the fight against an enemy superior in manpower and firepower.

The fortification plan was drawn up Major General Edvard Hanell, who worked in the pioneer department of the Headquarters, was assigned to draw up the fortification plan for the new main defense station of the Eastern border. Hanell was among the Finnish officers who received jaeger training from Germany during the First World War. In the 1920s, Hanell had obtained general staff officer training in France, and in the 1930s, as the director of the Military Academy, he significantly influenced the shaping of Finnish tactics and its training for army officers. Hanell was familiar with concrete construction before entering the military while studying at the Helsinki University of Technology. Salpaasema is generally considered Edvard Hanelli's life's work. While drawing up the fortification plan, Mannerheim appointed Hanelli as chief of the general staff and promoted him to lieutenant general. In this way, Hanelli gained more prestige and thus added impetus to the fortification planning, which had started sluggishly, slowed down especially by the dispute of the senior military command about the alignment of the main defense position on the terrain in southern Finland.

Mannerheim's solution says a lot about the importance given to fortification during the interim peace. On Mannerheim's commission, Lieutenant General Hanell prepared a fortification plan, which included the fortification of the entire new eastern border from the Gulf of Finland to the Arctic Ocean. The length of this defensive line – colloquially known as Salpalinja – totaled approximately 1,200 kilometers. The fortification plan also included the fortification of the archipelago in the eastern Gulf of Finland and the defense line to be built across Hankoniemi, which was leased to the Soviet Union, and is known today as the Harparskog line.

The strongest decision was made to fortify the area between the coast of the Gulf of Finland, which is an extension of the Karelian Isthmus, and Lake Kivijärvi on Luumäki, because it was the shortest road connection to the country's capital, Helsinki. Because of this, it was also considered the most likely main focus area for an enemy attack. In Järvi-Suomi, islands and inlets of lakes were mostly fortified. Here the defense was based on the abundant use of coastal artillery evacuated from Laatoka. North of Joensuu, only the most important east-west roads were decided to be closed with fortifications.

As a field fortress, the plan extended all the way to the coast of the Arctic Ocean. According to Hanelli's plans, the body of the defense station was formed by a network of machine gun side embrasures, around which the other parts of the defense line were planned. In other words, the salpalinja gun pits did not fire directly at the enemy from the front line as usual from the Mannerheim line. In the Winter War, it had been discovered that such dugouts were very vulnerable to direct fire from enemy artillery. The construction of a defensive line operating on the principle of flanking was significantly more expensive than the manufacture of dugouts firing from a direct frontal line, as the dugouts had to be built more densely than usual. On the other hand, the fortification works during the inter-peace period were no longer hindered by the chronic lack of money known from the 1930s, as almost 1.3 billion marks were allocated for the construction of the Salpa station - about five percent of the entire state budget in 1940–1941.

The fire of the strongest reinforced concrete bunkers can withstand, among other things, the continuous firing of a 155-millimeter cannon and the full hit of a one-thousand-kilogram flying bomb on the roof. In addition, the dugouts had to be gas-protected in case the enemy resorted to the use of battle gases against the dugouts.

For the coordination of the fortification works, the Fortification Office was established, located near Kouvola in Myllykoski. Civilian and military personnel familiar with fortification were gathered in the office - mainly civil engineers, officers of the pioneer navigator and office and financial staff. Office is perhaps a somewhat misleading designation for an organization,which was actually one of the largest wartime staffs. In June 1940, almost 150 people worked in the Fortification Office, and by the end of the year already more than 400.

The fortification plan drawn up by Hanelli was completed on May 8, 1940, and Commander-in-Chief Mannerheim approved it three days later, but the fortification work itself had already started in mid-April. The first spade sticks were sunk into the ground in Virolahti's Ravijoki on April 17, 1940. The practical implementation of the construction works of the new main defense line required seamless cooperation between the commanders of the army forces responsible for placing the equipment on the terrain and the technical managers of the construction works. Fortresses built in this way would get the best use out of both construction technology and combat operations. The employees of the fortress construction forces, which operated under the fortress office, had been hired for their duties with free labor contracts for civilian labor. The volunteer fortification works on the Karelian Isthmus before the Winter War were, as the name suggests, done without pay.

The main responsibility for procuring volunteer labor for the isthmus fortifications and organizing the work was borne by the Academic Karelia Society and the guardianship councils. However, after the Winter War, we were in a situation where the majority of potential volunteer fortifiers had remained in the service of the army. Therefore, the use of volunteer labor at Salpalinja's construction sites seemed to be an excluded option. Consequently, it was decided to obtain labor for the fortification sites at Salpa station by hiring civilian builders. The fortification work also offered a good opportunity to take care of the post-war unemployment in Finland, and since the need for labor was quite large, builders were hired all over Finland regardless of age and social background. Above all, residents of cities and towns, as well as the Karelian evacuee population, were wanted for work.

The use of rural residents as workforce for the fortifications was tried to be avoided, as the country's food production was wanted to be kept as efficient as possible. In the division of labor for the fortification, the principle was followed, according to which the army troops carried out, for example, the construction of battle trenches, the setting up of the barbed wire barrier, and other tasks handled with "axe and shovel"; while the construction workers hired for gainful work performed, for example, concrete pouring and excavation work, which required special professional skills and tools. For the most demanding mining and construction jobs, construction companies operating in the field were hired on contract contracts, which had the responsibility to put not only skilled labor to work, but also the required machines and special equipment, of which the army was in dire shortage. Qualified builders were attracted to work on the fortress with better than average wages.

In addition, the management of the construction sites also had a fairly wide salary range,thanks to which, if desired, competent and hardworking workers could be paid better wages for good work. The good wages are said to have attracted the best construction professionals of the time to the fortress sites during the inter-peace period. The fortified areas were located in many places in the wilderness, far from settlements and roads. Because of this, work started in many places with the construction of roads and wooden barrack villages for the fortifiers. The shack villages consisting of canteen, office and accommodation shacks became quite self-sufficient communities during the fortification works, where, in addition to the builders, office workers, cobblers, barbers, laundresses and lotts worked, who were responsible for the maintenance of the workers. However, many times, especially the older workers, alienated the sometimes rather restless life of barrack villages and preferred to live with local residents in apartment accommodation. The actual fortification was carried out by work groups formed for the task, made up of construction men, whose strength was on average 500 men. The work group was usually led by a construction foreman or engineer. Workgroups, on the other hand, were led by work districts, under which there were usually three to five workgroups.

During the Winter War, Finland's western neighbor, Sweden, had a strong desire to help the Finns. In February 1940, Sweden was already preparing to send a volunteer workforce to Finland to carry out fortification and construction work on the rear lines. The goal was to send 9,000 men to Finland equipped with work machines and tools. The first Swedes arrived in Finland already in March and formed the Svenska Arbetskåren work unit, whose strength rose to almost 1,000 men. A record 240 Norwegian volunteers had also arrived in Finland in the spring and winter. During March-April, the Norwegians had time to do some fortification work on the Kymijoki line that was under construction along Kymijoki, but they did not have time to participate in the fortification work at the Salpa station. At the beginning of April, Germany occupied Denmark and also attacked Norway, as a result of which the security political situation in the North changed radically. The Norwegian volunteers immediately returned to their home country, and no more workers from Sweden could be sent to Finland. However, SAK's employees who left for Finland remained in the fort in Virolahti, the area between Ravijoki and Säkäjärvi until their repatriation in June. The organization of the Svenska arbetskåren task force had already taken shape during the winter war, and it was able to start fortification work on the new eastern border before the formation of Finnish work units. The Swedish volunteers were accompanied by professional work management, which considerably accelerated the start of the actual fortification works.

The Swedish management and specialist professionals remained for a few months to train the Finns in, for example, rock mining technology,until they too were repatriated in September. However, the Swedes left in Finland the work tools, machines and vehicles they brought with them, of which there was a severe shortage in Finland. In addition to this, the Swedes donated 20 million kroner to the Finnish state, which corresponded to almost 240 million marks at the time. The sum was a total of about 20% of the financing need for the fortification works in 1940. Donation funds were used to buy more work machines and construction materials needed for the fortifications in Sweden, such as concrete reinforcement steel. Fortification works and local residents In the small towns on the eastern border, the way of life in the villages changed significantly after they became border guards as a result of the Moscow peace terms.

When the fortification work began, both army troops and civilians arriving for the fortification construction work poured into the villages. For example, by the middle of August 1940, a total of about 3,000 construction workers from outside the town had arrived in Miehikkälä with a population of 5,000. For example, the number of police officers in the border area had to be multiplied in order to maintain discipline. The local people behaved in a matter-of-fact manner, and the police's time was primarily spent curbing the behavior of the fortress workers (including alcohol smuggling and fights). Before the barrack villages were completed, a large part of the fortifiers stayed in the apartments of local residents, for which the original residents were of course paid appropriate compensation. Due to national defense reasons, the land property of private people could not be protected either, but the fortifications had to be placed in the most advantageous places for defense. This could mean that sometimes even reinforced concrete dugouts, stone barriers and battle trenches were built in the yards of houses.

In places, the farms could even become unviable due to the fragmentation of the fields, but of course the landowners received compensation from the state for the reclaimed land and for the harm caused by the fortifications to agriculture and forestry. Having become wiser from the experiences of the Winter War, the municipalities of the border region also understood the importance of the fortification works for the preservation of independence in the future, as a result of which it was easier to tolerate the disadvantages caused by the fortifications to normal life and living. The start of the fortification work also offered many new earning opportunities to local residents. Products from their own farms were traded to supplement the diet of the fortress workers, and the builders who lived with the locals also received a fair payment for accommodation.

Of course, the fortification works themselves also offered many local residents a job. Although Linnoitutoimisto's goal was to hire people primarily from the urban population, it was also possible to hire qualified construction workers from local residents if necessary. Especially for many young people who lived in border guards, the fortress work became the first gainful job of their life.

Although according to the official regulations, only adults could be hired, many local young people were hired even at the age of 15 to work at the fortress sites, for example as messengers, blacksmiths' assistants or carrying drill bits. The arrival of thousands of young men on small farms caused considerable changes in the local social life. For example, Miehikkälä, with a population of about 5,000, had about 10,000 young men at the time of the interim peace, both in the army's gray and fortress jobs. Thus, there were good conditions for dating when local young women met young men from other parts of Finland, e.g. at corner dances and evenings organized in the fortress towns. From time to time there were fierce battles between the fortress workers, soldiers and locals for the attention of the few young women in the locality.

Despite the fierce competition, relationships closer than "dance company" were sometimes born, which later led to marriage. Achievements and work description of fortifications in the 1940s The number of builders working on fortification sites rose continuously during the peacetime period and reached its peak in March 1941, when more than 35,000 civilian builders worked in addition to the army units. More than 1,000 trucks were in use at the construction sites, about half of the entire country's truck stock. The Lotta Svärd organization was responsible for the refurbishing of the workers, there were at most more than 2,000 lotties in both refurbishing and office tasks. Looking at the amount of labor used, Salpa station is still the largest construction project implemented during Finland's independence. The job was so big that, viewed from different perspectives, it can be considered to have actually employed the entire Finnish people. The impressiveness of the work achievements is further increased by the fact that in the 1940s fortifications were still largely based on manpower. Timber was procured from the forest with axes and hand saws, and especially in field fortifications a lot of round timber was used directly from the terrain. In earth excavation, few excavators were needed for the sites of base fortifications, while the excavation of field fortifications was carried out by shovel work.

In quarrying the rock, some pneumatic hand drills, mostly from Sweden, were available for making stake holes, but usually, for example, the breaking of obstacles was carried out with a hammer and hand drill method. The finished barriers were winched from the truck platforms to the ground, mostly with hand-operated tripod cranes. In addition to trucks, the transports were often also horse-drawn. In both cases, transporting the material to the destination was quite difficult, as the fortifications were mostly made for tactical reasons in difficult terrain. For example, concrete often had to be moved from the truck bed to a hard-to-reach casting site with wheelbarrows. The most typical Salpalinja reinforced concrete dugout is a machine gun and 20-man accommodation dugout,of which a total of 168 were built.

Bedrock was used in the fortifications whenever possible, as the structures became more durable and the need for concrete was less. If rock was not available, up to 560 cubic meters of concrete had to be used to cast the underground dugout. The truck's engine during the fortifications - usually equipped with a wood carburettor to save liquid fuels - usually did not develop much power and was only able to transport a cube of concrete to the casting site. More than 500 truckloads of concrete were therefore needed to pour one ditch, transported from the concrete mixing plant to the casting site. 45 tons of concrete steel and a total of 5,000 50-kilogram cement sacks were needed to build the ditch. In total, about 10,000 tons of various masses were moved during the construction of one ditch. When the stone barrier was being built, a truck from the 1940s - as well as a horse - was only able to transport one barrier stone weighing about three tons to the barrier stone site at a time. During the construction of the stone barrier, an average of 1,700 stones were erected per kilometer, so a total of nearly 400,000 individual barrier stones had to be broken up, moved and erected over a distance of 225 kilometers.

Salpa station on the back lines of the Continuation War Salpa station was never completed. Construction work was interrupted in the summer of 1941, when the continuation war against the Soviet Union began on June 25, 1941. The bodies of the work groups that worked on the fortifications were formed into fortress construction battalions, which in 1941–1942 carried out road and airfield improvement works, repaired bridges, built barracks and renovated buildings located in the recaptured area. During the initial offensive phase of the Continuation War, Salpalinja was far behind. The weapons and other related equipment used at the Salpa station were moved during the station war that followed the establishment of the front line to strengthen the front line defense stations. A large amount of timber, barrier stones and barbed wire were also transported from the Salpalinja to the new defense positions, which were built both in Eastern Karelia and on the Karelian Isthmus. For example, the barrier stones for the VT line built on Kannas had to be imported from elsewhere or cast from concrete, because no suitable barrier stones could be found in the sandy terrain of Kannas.

On June 9, 1944, the Soviet Union launched a major offensive on the Karelian Isthmus, which fairly quickly broke the Vammelsuu–Taipale defense line built on the Isthmus during the Continuation War in its weakest fortified area, Kuuterselä. The Finns retreated to the significantly weaker fortified ViipuriKuparsaari–Taipale defense line, where battles began to take place in the last days of June. At the same time, all existing fortress construction battalions were concentrated at Salpa station. In the summer of 1944, the most urgent tasks of the fortress construction forces concentrated on the Salpalinja were to improve the anti-tank capability of the line and to complete the network of battle and communication trenches.In addition, the fire network formed by the reinforced concrete dugouts built during the intermission had to be supplemented with wooden field fortifications, the firing range had to be cleared and the station had to be deepened to strengthen the rather narrow fortification zone built during the intermission.

In contrast to the peacetime period, in the late stages of the Continuation War, Salpa Station was staffed by construction crews made up of conscripts, including prisoners and mentally ill patients, instead of paid civilian labor. New technology introduced during the Continuation War was also used. For example, the quick production of concrete accommodation dugouts was made possible by ball dugouts cast in element molds and finished using the suction concrete method, of which more than 250 were built in total in Salpalinja in the areas of Virolahti, Miehikkälä, Lemi and Lappeenranta. To limit the movement of enemy tanks, a tank trench was built, which proved to be useful in the continuation war. However, "traditional" methods were still used in the preparation of the trench, because the edges of the trench could not have been made steep enough with an excavator. Because of this, the excavation had to be carried out as shovel work, where approximately nine cubic meters of earth had to be moved by manpower from a distance of one meter.

During July-August, the Soviet Union's major attack was repelled both on the Karelian Isthmus and in Eastern Karelia. The armistice between Finland and the Soviet Union entered into force on 4–5 September. and an armistice was concluded on 19 September 1944. The order to stop the fortification works was given on September 24, although the unfinished works could still be completed after the order was given. This time too, not all the planned tasks were completed, for example because a lot of the equipment needed for the fortification work had been destroyed on the Karelian Isthmus during the withdrawal phase.

The fortification works during the inter-peace period were interrupted by the start of the Continuation War, while in the fall of 1944 the fortification works ended with the end of the war. Effective working time for the construction of the Salpa station was used during the interim peace and in the final phase of the Continuation War, a total of about one and a half years. The Salpalinja lost its military significance quite soon after the end of the Second World War, as the line-like defensive positions proved to have outlived their time. After the wars, there was a transition to regional defense, where instead of linear defense, the emphasis is on defending the country in the depth of the area, wearing down the enemy. Secrecy of the fortification works It was natural to try to hide the important fortification works from the Soviet Union as precisely as possible. Numerous instructions were sent to the construction sites from the fortress office, for example regarding the handling of secret documents and the guarding of the construction sites. Photography of the fortifications was also strictly prohibited without a separate permit.

The most important information to be kept secret was the technical details of the fortifications and the location of the equipment on the terrain.By acquiring the information in question, it would have been easy for the enemy to find out the possible weak points of the line and use them to try to break the defensive position by exploiting its weaknesses. Efforts were also made to monitor the employees of the fortification sites and their reliability. Using voluntary informants and a "black list" of suspicious employees, an attempt was made to exclude suspicious employees from the working groups who were thought to be possibly leaking information about the fortification works either to the Finnish communists or directly to the Soviet Union. Despite attempts at encryption, information about the existence of the Salpa station also reached the Soviet Union via various routes.

Both Soviet spies and Finnish informants hired by the Soviet Union moved around the fortress sites. It was not possible to catch all the people who moved around the border area in the dark, because the control of the areas was made difficult, for example, by the explosive increase in the population of the border area keepers as a result of the arrival of the fortress workers. Many spies from the fortress sites were indeed caught in the act, but completely blocking the information leak proved to be impossible. In addition to this, Salpalinja's massive construction sites were easily visible with the help of aerial surveillance, for example - in good weather even from the other side of the border, and in addition, dozens of airspace violations were committed by the Soviet Union during the interim peace.

In addition, the number of personnel at the Soviet Embassy in Finland increased considerably during the interim peace, and embassy employees were known to move around the border region collecting information about the fortification works. A potential spy didn't even have to go to the fortress site itself, because without a doubt it was often easy to deduce from afar what the Finns had gone to the vertical forest to do based on the sounds of drilling drills and rock quarrying. The information that ended up on the wrong side of the border through espionage was quite accurate and detailed in some places. This can be deduced, for example, from the Russian reconnaissance map that the Finns got in the hands of in connection with the recapture of Sortavala in the summer of 1941, on which the route of the Salpalinja line on Finland's eastern border was very precisely marked.

Based on the information obtained afterwards, it has also been possible to state that the knowledge of the existence of the Salpalinja influenced the Soviet Union's strategy against Finland already during the interim peace. In the attack plans drawn up against Finland after the Winter War, under the leadership of the Red Army, the idea was to go around the most heavily fortified southern part of the Salpalinja through the difficult-to-navigate waterways of Lake Finland. Also at the end of the continuation war, the knowledge of the existence of the Salpa station undoubtedly had an effect on the fact that the Soviet leadership decided to stop the major attack against Finland, which had been stuck in place on the Vyborg–Kuparsaari–Taipale defense line after the capture of Vyborg.

It was known in the Kremlin, that a considerable number of combat troops would have been needed to break the Barrier Line, which at that moment was more needed in Central Europe on the anti-German front. In this sense, the information that ended up on the "wrong" side of the eastern border from the Salpa station was actually of considerable benefit to Finland. Almost immediately after the signing of the armistice agreement, the Allied Control Commission arrived in Finland to keep an eye on the implementation of Finland's armistice terms. Almost from the very beginning, the commission, consisting mainly of Soviets, demanded to see all the documents relating to Salpaasema and inspected every line of equipment in detail on the ground under the guidance of former Fortress Office employees.

At the latest at this stage, all relevant information about Salpalinja also ended up in the possession of the former opponent. The importance of the Salpa line The construction of the Salpa station was a huge effort for war-torn Finland in the 1940s, which Edvard Hanell, the director of the fortification works himself, characterized as "a show of strength for the entire Finnish engineering community". During the fortification works, various excavation and concrete construction techniques were developed, which have since come into use also in peacetime construction works. In the construction of the lock line, the latest technologies in the field were used, combined with the experiences gained in the winter war, which resulted in one of the best defensive positions of the Second World War.

Measured in terms of work achievements, the work effort of the fortifiers is impressive: a total of 728 different reinforced concrete dugouts, gun emplacements and caves were built in Salpalinja; more than 3,000 wooden field forts; about 225 kilometers of tank rock barrier line; 315 kilometers of barbed wire barrier, 130 kilometers of armored trenches and more than 350 kilometers of battle and communication trenches. In the battles of the summer of 1944, among Finnish soldiers, the Salpa station was seen as a kind of "last line of defense", which has been said to have formed the spiritual backbone of the army in the fighting battles of the summer of 1944. The soldiers knew that the Salpalinja, located far in the rear, was the strongest defense line ever built in the country, where the troops would still be able to concentrate even if the front might break. The Finnish army proved to be a very capable defender of its country during the Second World War.

Undoubtedly, when occupying the Salpalinja, it would have created such an obstacle for the opponent that to break it, the biggest and toughest battles in the history of Pohjola would have had to be fought on the line. This was also known in the Soviet Union. It was not possible to bypass the Salpa station, and after the heavy battles of the early summer, the country's military leadership was no longer willing to undertake an attempt to break the Salpa Line, which would most likely require heavy crew losses. The Soviet leadership had discovered that the Finns' defense could not be easily breached even with great superiority, and it was decided to direct all the troops moving from the Finnish front to a more important task.

The solution undoubtedly saved a large number of lives on both sides. During the Cold War that followed the Second World War, the existence of the Salpalinja was not talked about very loudly in Finland - after all, the existence of a massive defense line crossing the country's eastern border was a bit embarrassing in a country that had a valid agreement on friendship, cooperation and mutual aid with the Soviet Union. In practice, the only ones who, besides the army personnel and the fortress workers, were aware of and remembered the existence of the Salpa station were the residents of the municipalities crossed by the Salpalinja, who had been given to understand that it would be best to keep quiet about the subject.

After the end of the Cold War, it was possible to renovate various Salpalinja sites for museum and tourist use. Model examples of these are, among others, the Bunker Museum in Virolahti and the Salpalinja Museum in Miehikkälä in Southeast Finland, as well as numerous other sites located along the eastern border from the Gulf of Finland to Lapland. Salpalinja is a concrete monument and memorial of the past in today's Finland. When visiting the defense line built to protect the eastern border, regardless of where the traveler is, he gets a chilling impression of the Finns' strong will and hard efforts to preserve independence during the difficult times of the Second World War.

With a total length of 1,200 km, the Salpa Line is one of Europe’s strongest and best-preserved World War II fortification lines. Fortification work on the Salpa Line ended after the end of the Continuation War in 1944, but the Finnish Defence Forces maintained the fortifications until the 1980s. In 2003, the Salpa Line was transferred from the Ministry of Defence to the Ministry of Finance, and the fortifications are nowadays taken care of by Senate Properties. With the development of military technology, the fortifications have lost their military significance, and focus has been placed on their tourism and recreational values. Some of the fortifications have been refurbished and taken into museum and tourism use. Today, the Salpa Line is comparable with sites protected under the Antiquities Act.

Right after the Continuation War, some of the Salpa Line’s wooden field fortifications and barbed-wire obstacles were taken down and used as construction supplies. In the course of time, a small number of the stone obstacles have been cleared and some trenches and anti-tank ditches filled to make it easier to get around, cultivate land and conduct other business. The wooden structures left in the terrain have rotted over the decades, but the reinforced concrete bunkers, accommodation caves excavated in rock and anti-tank stones are well preserved.