Titicaca is a large, deep lake in the Andes on the border of Bolivia and Peru, often called the "highest navigable lake" in the world. By volume of water and by surface area, it is the largest lake in South America. Lake Maracaibo has a larger surface area, but it is a tidal bay, not a lake.
Lake Titicaca has a surface elevation of 3,812 m. The "highest navigable lake" claim is generally considered to refer to commercial craft. Numerous smaller bodies of water around the world are at higher elevations. For many years, the largest vessel afloat on the lake was the 2,200-ton, 79-metre SS Ollanta. Today, the largest vessel is most likely the similarly sized train barge/float Manco Capac, operated by PeruRail.
Coordinates -15°53'9.129" N -69°20'48.256" E