Puruvesi is a
lake in Eastern
Finland. The lake is located in
Kerimäki,
Kesälahti and
Punkaharju municipalities. Part of the
Saimaa lake system, it borders on the sub-lake system of
Pihlajavesi to the south. As is the case of other lakes of Saimaa, it has numerous islands and consists of numerous open lake areas, of which largest are Hummonselkä, Pajuselkä, Sammalselkä, Mustanselkä, and Ruosteselkä.