Lima/Callo Area, Peru May 1997 The coastal area of Peru is a desolate, rocky or sandy desert that extends from Ecuador to Chile. As seen on this image, the arid environment is broken only by short-flowing rivers that rapidly descend through the western flank of the Andes Mountains as deeply eroded and incised river valleys. Over fifty percent of Peru’s population lives in the coastal valleys where irrigated agriculture is possible. The capitol, Lima, and its port city of Callao (barely visible in this small scale picture), are located along the coast near the center of the image. The island of San Lorenzo is located immediately offshore of the Callao-Lima urban area. The human settlements in the coastal valleys are totally dependent on water that flows from the Andes Mountains along canals and aqueducts that were built thousands of years ago