Mount Filin is an interesting military-historical museum of the World War II. It is located 3 kilometers north of the city of Lahdenpohya, near the shore of Lake Ladoga. The museum is one of the largest military bunkers in northern Europe. It was made inside a granite rock. 

After the outbreak of World War II, most of Karelia, up to Lake Onega, was occupied by the Finnish army. At the beginning of the war, Finland was an ally of Germany. The construction of the Filin Bunker began in 1943, when the strategic situation on the Eastern Front was radically changed. The Germans had already lost the Battle of the Kursk Bulge, and there was a threat of a general Soviet offensive. 

In 1944, the Filin Bunker was ready. A natural grotto in the rock was used to cut down halls inside the granite rock. Their area was 750 m2. The command and staff bunker of the Finnish Army was created here. The barracks for the soldiers of the Finnish were built nearby. The Filin Bunker has two large rooms and a medical room. It has two exits and all the necessary communications. 

The Finnish army did not have to use the Filin Bunker for its intended purpose. After the successful Operation Bagration in 1944, Soviet troops destroyed the German Army Group Center, after which they launched an offensive on Warsaw. At the same time, the Soviet troops launched an operation against Finland. The main battles took place in the area of Vyborg, significantly south of Lahdenpohya, where the Filin Bunker was located. On August 25, 1944, the President of Finland, Marshal Mannerheim, sent a letter to Stalin with a proposal to conclude a peace treaty. As a result, the Karelian Isthmus and the lands west of Lake Ladoga were transferred to the Soviet Union. 

In the Soviet years, the Filin Bunker was used as a warehouse for a long time. The Military History Museum was established here in 2016. Here you can see how the rooms and communications were arranged inside the granite rock. The museum`s halls tell in detail about the course of the Soviet-Finnish war from 1940 to 1944. A separate exhibition is dedicated to the geology of the surrounding rocks. In front of the museum, you can see an exhibition of military equipment. It is also a must to climb to the top of the mountain to see the Karelian nature.