Lake Chilwa is the second-largest lake in Malawi after Lake Malawi. It is in eastern Zomba District, near the border with Mozambique. Approximately 60 km long and 40 km wide, the lake is surrounded by extensive wetlands. There is a large island in the middle of the lake called Chisi Island. The lake has no outlet, and the level of water is greatly affected by seasonal rains and summer evaporation. In 1968, the lake disappeared during exceptionally dry weather.