A river of central Peru, rising in the Laguna de Villafra in the western Cordilleras, 7 m. from Caylloma, a village in the department of Arequipa, and less than 100 m. from the Pacific coast. It flows first north-easterly, then north-westerly past Cuzco to the mouth of the Perene tributary, thence east and north to its junction with the Ucayali at io° 41' S. lat., and 73° 34' W. long. It is known as the Apurimac only down to the mouth of the Mantaro tributary, 11° 45' S. lat. and 1325 ft. above sea-level. Thence to the mouth of the Perene (984 ft.) it is known as the Ene, and from that point to its junction with the Ucayali (859 ft.) as the Tambo.