Lake Titicaca, at an altitude of 3,812 m (12,507 ft), is one of the highest navigable lakes in the world. The sapphire-blue lake measures 233 km (145 mi) from northwest to southeast and 97 km (60 miles) from northeast to southwest, making it the largest lake in South America.

It has an indented shoreline and there are 36 islands in Lake Titicaca. Two of them, Isla del Sol and Isla de la Luna are the most important Inca's creation myths. Isla Suriqui is famous for its totora reed boats, while on Isla Kalahuta you'll see numerous stone tombs. Isla Incas is said to have an underground network of passageways that links it with the ancient Inca capital of Cuzco in Peru.

The principal town on the islands in Lake Titicaca is Copacabana in Bolivia. The main town on the Peruan side of the border is Puno, which is also the lake's major port. The town has a beautiful Moorish-style cathedral and once a year the Fiesta de la Virgen de Candelaria is celebrated there.

If you visit the region you should wear protective head gear, as the amount of ultraviolet radiation in the region is extravagant because of the thin air resulting from the high altitude. About half the lake lies on Peruan territory, while the other half is in Bolivia.