evidence: Lake Victoria is one of the African Great Lakes. With a surface area of approximately 59,947 km2 (23,146 sq mi),[6][7] Lake Victoria is Africa's largest lake by area, the world's largest tropical lake,[8] and the world's second-largest fresh water lake by surface area after Lake Superior in North America.[9] In terms of volume, Lake Victoria is the world's ninth-largest continental lake, containing about 2,424 km3 (1.965×109 acre⋅ft) of water.[7][10] Lake Victoria occupies a shallow depression in Africa. The lake has an average depth of 40 m (130 ft) and a maximum depth of 80–81 m (262–266 ft).[7][10][11] Its catchment area covers 169,858 km2 (65,583 sq mi).[12] The lake has a shoreline of 7,142 km (4,438 mi) when digitized at the 1:25,000 level,[13] with islands constituting 3.7% of this length.[14]