The Salpa-line Fortification
The Salpa-line fortification was built in 1940 - 41 and 1944 to secure the eastern border of Finland, by an order of Marshal Mannerheim. In the southern end of Kongonsaari Island, there is a rock cavity, through which it is possible to walk to the middle of the cape. Those, who dare to walk to the other end, will find old battle trenches and great scenery there.
The fortification extends itself from the Gulf of Finland to as far as the Arctic Sea (about 1200 km), and it was built by about 35 000 men. The backbone of Salpa-line consists of more than 700 dugouts made of ferroconcrete. In addition, the fortification included wooden entrenchments, anti-tank rocks, barbed wire entanglements and trenches. Building this fortification was never finished, and its durability was never tested in a military operation.
There is no guidance to the cave of Pihlajavesi (61°39,44' 29°05,38'), and there are no constructed facilities for visitors. Those, who are brave enough to go into the narrow cave, should have a torch and rubber boots.