small island in the Pacific ocean, near the coast of Peru, situated W. long. 81°, S. lat. 1°. It is also the name of a city of Peru, capital of the province of La Plata, situated in W. long. 66° 30', S. lat. 22° 30'; and also the name of a great river of Peru, which rising in the province of La Plata, and running south-east till it joins the river Paragua, discharges itself into the Atlantic ocean, below the city of Buenos Ayres.