La Plata (La Plah'ta), the capital of the Argentinian province of Buenos Ayres, was founded in 1884, after Buenos Ayres City, from which it is about 30 miles SE., had been made the federal capital. The new city was rapidly built, with wide streets, and over a score of squares; the central portion is lit with the electric light, and there are tramways. Buildings of note are the handsome capitol, an observatory, and a fine railway station. Cottons and woollens are manufactured ; and a canal connects a harbour here with a larger outer one at Ensenada, on the La Plata River. Pop. 75,000.
La Plata, RIo de, a wide estuary of South America, between Uruguay on the north and the Argentine Republic on the south, through which the waters of the Parana and the Uruguay sweep down to the ocean. It is about 200 miles long, 28 wide at Buenos Ayres, and 140 broad at its mouth. The northern shore is somewhat steep and lofty, but that along the province of Buenos Ayres is low and flat, with wide sandbanks. The estuary has thus no shelter from the tempestuous storms from the SW. ; and even the only good harbour, that at Montevideo, is open to the SE. The outflow of the estuary is exceeded only by that of the Amazon ; the yellow, muddy stream is recognisable 60 miles out at sea. The estuary was discovered in 1515 or 1516 by Diaz de Solis, who was shortly afterwards roasted and eaten by the Indians on its bank. Plata is the Spanish word for 'silver.' See Sir Horace Rumbold's Great Silver River (2d ed. 1890).