Latin American Studies.org: The IncasINCAS, an American Indian people of Peru who in the two centuries before the Spanish discovery of America conquered an area stretching from the southern border of present-day Colombia to central Chile. Centering on the city of Cusco (Cuzco) in the Peruvian Andes, the Inca domain included the coastal and mountain regions of Ecuador, Peru, Bolivia, and the northern areas of Chile and Argentina--the only true empire existing in the New World at the time of Columbus, and the greatest political achievement of the American Indians.