The lake shared by Peru and Bolivia that is often called the world’s highest navigable lake is Lake Titicaca.
Lake Titicaca sits in the Altiplano of the central Andes at about 3,812 metres above sea level. Its large surface area and depth support significant human communities, and boats have operated on the lake for centuries. The international boundary between Peru and Bolivia crosses the lake.
The lake has two main sub-basins, connected by the narrow Strait of Tiquina. Its largest city is Puno on the Peruvian shore, while Bolivia’s important lakeside center is Copacabana. The Uros people are associated with floating reed islands in the lake’s Peruvian sector.
The phrase “highest navigable lake” depends on how navigability and lake size are defined, so it is best treated as a widely used description rather than an absolute physical category. Lake Titicaca remains one of the Andes’ best-known geographic landmarks.