Volchya
The Volchya is a tributary of the Vuoksi on the Karelian Isthmus west of the Saint Petersburg-Hiitola railroad and flowing northwards from the Lembolovo Heights. It is long, and has a drainage basin of. Its major tributaries are in turn the Smorodinka, the Belaya, the Goryunets and the Petrovka. The Volchya River's width is about in the lower reaches, where it flows in a narrow valley, with meanders and oxbow lakes. The Volchya is shallow and unavailable for navigation
The river is crossed by the Sosnovo – Pervomayskoye road on Lembolovo Heights, Sosnovo – Borisovo – Michurinskoye road at Razdolye and by the Losevo – Yagodnoye road at the lower portion of the river.
Since 1928 there is a little hydroelectric plant on the river not far from Petäjärvi, which was the largest private hydroelectric facility in pre-Winter War Finland.
The entire river was a boundary between the Kingdom of Sweden and Novgorod Republic as defined in 1323 in the Treaty of Nöteborg. The higher reaches of the Saijanjoki to the south of the Tungelmanjoki and the Tungelmanjoki itself constituted part of the Russia-Finland border in 1811–1940. Now that stretch of the Volchya River divides Priozersky and Vyborgsky District from Vsevolozhsky District, while the Smorodinka marks another part of the boundary between Priozersky District and Vsevolozhsky District.
The river was renamed from the Saijanjoki to the Volchya in 1948, just like the vast majority of other Finnish hydronyms and toponyms on the territories ceded by Finland to the Soviet Union as a result of the Continuation War.