Río de la Plata

The Río de la Plata (called River Plate in British English) is a river in Argentina. It is an estuary made from the Uruguay River and the Paraná River. These rivers are on the border between Argentina and Uruguay. It is about long.
The Río de la Plata widens from about at the inner part to about at its mouth. Buenos Aires is on its western shore. Montevideo is on its northern shores.
The Río de la Plata is home for the loggerhead sea turtle, green sea turtle, leatherback sea turtle, the rare La Plata dolphin, and many species of fish.
Battle of the River Plate (1939).
The first naval battle of the Second World War was fought near the River Plata. The Kriegsmarine "pocket battleship" "Admiral Graf Spee" was engaged by the Royal Navy cruisers, , and off the estuary of the River Plate in December 1939. 
The German ship retired up the estuary with a crippled fuel system and put into port at Montevideo. A few days later, rather than fight outgunned against the British, she was scuttled in the estuary. This engagement was part of the early Battle of the Atlantic skirmishes.