Lake on the boundary between Macedonia, Albania, and Greece.
It is 14 mi (23 km) long, 8 mi (13 km) wide, 2,800 ft (853 m) above sea level, and it drains northwest into Lake Ohrid through a subterranean channel. South of it is Little Prespa Lake, which contains the island of St. Achilius; the island was an early capital of Bulgarian Tsar Samuel in the 10th century. It became a tourist and fishing centre in the 1970s.