Lake Titicaca is a lake located on the border of Peru and Bolivia. It sits 3,811 m (12,500 ft) above sea level, making it the highest commercially navigable lake in the world. By volume of water, it is also the largest lake in South America (Lake Maracaibo has a larger surface area, but it is often disregarded as it is directly connected to the sea).
The lake is located at the northern end of the endorheic Altiplano basin high in the Andes on the border of Peru and Bolivia. The western part of the lake lies within the Puno Region of Peru, and the eastern side is located in the Bolivian La Paz Department. The lake is composed of two nearly separate sub-basins that are connected by the Strait of Tiquina which is 800 m (2,620 ft) across at the narrowest point. The larger sub-basin, Lago Grande (also called Lago Chucuito) has a mean depth of 135 m (443 ft) and a maximum depth of 284 m (932 ft). The smaller sub-basin, Wiñaymarka (also called Lago Pequeño, "little lake") has a mean depth of 9 m (30 ft) and a maximum depth of 40 m (131 ft). The overall average depth of the lake is 107 m (351 ft).