The small inland lake of Käsmu sits about 3 km south of the village, in pine forest on the inland side of the coastal road. The lake is shallow and clear, with sandy bottom and a small wooden bathing platform — warmer than the sea by several degrees in summer and popular with families who want to swim without the bracing chill of the Gulf. Pike and perch fishing is allowed with a permit.
A marked footpath runs around the lake (about 5 km) and connects through to the main peninsula trail. The lake is named for the village, not the other way around — the village is the older name, used for the wider area since the medieval period.