River Plate

River Plate (Spanish, Río de la Plata, “Silver River”), estuary of the combined Paraná and Uruguay rivers, south-eastern South America, forming a marine inlet between Uruguay and Argentina. It is about 230 km (143 mi) wide at its mouth and tapers gradually inland for a distance of about 274 km (170 mi) to the delta of the Paraná River. River Plate is of major economic and commercial importance to the region. The best natural harbour on the estuary is at Montevideo, Uruguay. Artificial harbours have been constructed at La Plata and Buenos Aires, Argentina. The estuary was discovered in 1516 by the Spanish explorer Juan Díaz de Solís, visited by Ferdinand Magellan in 1520, and received its present name from the Italian-born navigator Sebastian Cabot, who explored it between 1526 and 1529. Its banks were settled in the following decade by Pedro de Mendoza, a Spanish soldier and colonizer. Jesuit missions established nearby in the 17th and 18th centuries were designated a UNESCO World Heritage Site in 1995.