Frontier City of Petroskoi / Äänislinna

Once the bustling frontier city of Petroskoi (Karelia/Soviet Union) was in Finnish hands in 1941, the name was quickly changed to Äänislinna (‘Castle by Lake Ääninen’). During the next few years Finns opened schools serving both the local population as well as the conquering soldiers. In addition to the institutions of higher education, the Finns also established concentration camps for civilians of Russian ethnicity which they operated until the Red Army liberated the area. Six camps were set up in Äänislinna, with 23,984 civilians of Russian ethnicity confined in them. Civilians of Finnish, Karelian or other Finnic descent were not interned into these camps. Some of the camps were old Soviet camps and some only fenced city areas. One source estimated almost 4,000 people perished there, primarily because of malnourishment, most dying during the spring and summer of 1942. The city was occupied by Finnish troops for nearly three years before it was retaken by Soviet forces on June 28, 1944. This image was taken from the ski-jump tower, looking towards Lake Ääninen, on 17 October 1941

Source :

Book "Finland at War: The Continuation and Lapland Wars 1941-45" by Vesa Nenye, Peter Munter, Toni Wirtanen and Chris Birks 

https://en.wikipedia.org/wiki/Petrozavodsk