The
Vuoksi (; ; ) is a river running through the northernmost part of the
Karelian Isthmus from
Lake Saimaa in southeastern
Finland to
Lake Ladoga in northwestern
Russia. The river enters Lake Ladoga in three branches, an older main northern branch at
Priozersk (Käkisalmi), a smaller branch a few kilometres to the north of it, and a new southern branch entering further southeast as
Burnaya River (Finnish: Taipaleenjoki), which has become the main stream in terms of water discharge. Since 1857, the old northern distributaries drain only the lower reaches of the Vuoksi basin and are not fed by Lake Saimaa. The northern and southern branches actually belong to two separate river systems, which at times get isolated from each other in dry seasons.