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). Suriqui in the Bolivian part of lake Titicaca is thought to be the last place in the world where the art of reed boat construction survives, at least as late as 1998. Craftsmen from Suriqui helped Thor Heyerdahl in the construction of several of his projects, such as the reed boats Ra II and Tigris, and a balloon gondola.