The Province of Buenos Aires is the largest and most populous province of Argentina. It takes the name from the city of Buenos Aires, which used to be the provincial capital until it was federalized in 1880. The current capital of the province is the city of La Plata, founded in 1882.
The province limits to the north with Entre Ríos and Santa Fe; to the west, with Córdoba, La Pampa and Río Negro; to south and east, with the Atlantic Ocean. The entire province is part of the Pampas geographical region.