The Matanza River is known by several names, including, in Spanish, Rio de la Matanza (“the slaughter river”), or simply Riachuelo (“little river”). It is a 64-kilometre (40 mi) stream in Argentina that originates in the Buenos Aires Province and defines the southern boundary of the Buenos Aires federal district. It empties into the Rio de la Plata between Tandanor and Dock Sud. The La Boca neighbourhood and the Boca Juniors football club are located near the Riachuelo’s mouth. The Spanish word boca means “mouth”. Full HD.