The modern borough was created in 1970, when the center of Mexico City was split into a four boroughs with the other three being Benito Juárez, Cuauhtémoc and Miguel Hidalgo . The borough was named to honor Mexican Revolution General Venustiano Carranza . By the end of the decade, the entire territory of the borough was urbanized with the exception of the Peñón de los Baños and a reservoir area called the Bordo de Xochiaca, which is now mostly green space.