Lake Nicaragua, lake in southwestern Nicaragua, the largest lake in Central America. The lake is 164 km (102 mi) long and has a maximum width of about 72 km (about 45 mi). It is roughly oval in shape and covers 8,000 sq km (3,100 sq mi). The chief port is Granada. The lake contains the island Zapatera in the north, the Solentiname Islands in the south, and between them the island Ometepe, on which are the twin volcanoes Concepción and Maderas. Lake Nicaragua contains sharks, tarpon, swordfish, and other fish normally found only in saltwater environments.