Sediment-filled Lake Tana, the largest lake in Ethiopia, is visible in this near-vertical photograph. Located near the center of the high Ethiopian Plateau, Lake Tana covers 1400 square miles (3625 square kilometers). The lake is 47 miles (76 kilometers) long, 44 miles (71 kilometers) wide, and sits at an elevation of 6000 feet (1830 meters) above sea level. One of the many small streams feeding the lake is believed to be the source of the Blue Nile River. Lake Tana drains into the Blue Nile, which shortly thereafter plunges over the high Tisisat Falls (not visible in the photograph) south of the lake and turns southeast into a deep, rugged canyon. Visible are portions of the Choke Mountains south of the lake; the rugged Amhara Plateau west of the lake; and the islands of Dega and Dek, sites of historic monasteries, in the south-central portion of the lake.