Petrovskoye (Finnish: Petäjärvi; Russian: Петровское) is a rural locality on Karelian Isthmus, in Priozersky District of Leningrad Oblast. Before the Winter War and Continuation War, Petäjärvi was a prosperous village of the Sakkola municipality of the Viipuri province of Finland. In 1948, after the war, Petäjärvi was renamed to Petrovskoye, but the railway station of the Saint Petersburg-Hiitola railroad serving it retained its name, as there had already been another station with the name Petrovskoye in Leningrad Oblast.
In 1928, not far from Petäjärvi on the river Saijanjoki a little hydroelectric plant was constructed, which became the largest private hydroelectric facility in pre-war Finland (owned by Leonard Sääksjärvi). [1]