The Amazon is the longest river in the South America. It originates in the Peruvian Andes, and flows approximately 6, 450km (4, 000 miles) to its mouth in the Atlantic Ocean. It is the world’s second longest river. No other river approaches its volume of flow, which exceeds that of the world’s 10 next largest rivers, combined. Another large river system in South America is that of Parana, Paraguay and Uruguay rivers, the waters from which empty into the Plata estuary. The Parana River is navigable for ocean-going vessels as far upstream as Rosario, Argentina. A large combined bridge and dam completed in 1981at Salto Grande Marks the head of Navigation on the Uruguay River. Other navigable rivers in South America include
the Magdalena River in Columbia, the Orinoco River in Venezuela, and the Sao Francisco River in Eastern Brazil. Of these, the Magdalena carries the largest amount of general cargo traffic. The Sao Francisco is more significant for its hydroelectric potential than for its navigability. On the other hand, South America has few lakes and considerable size. Lake Titicaca (although not the largest) is the highest navigable body of water in the world. The elevation of its surface is 23, 810 meters (12, 500 ft.) above sea level. Lake Titicaca is shared by the countries of Peru and Bolivia, and regular hydrofoil service is available between them. Lake Maracaibo, in Venezuela, the largest body of water in South America, is connected to the Caribbean Sea by a narrow inlet. Maracaibo is mostly freshwater, shallow and punctuated frequently by petroleum derricks. Rather more picturesque is the Andean Lake District of Argentina and Chile, a recreational zone reminiscent of Switzerland.