This color infrared photograph of more than half of El Salvador helps to understand why the capital, San Salvador, has been partially or completely destroyed by devastating earthquakes and volcanic activity nine times since 1528—the city (whitish area in the center of the photograph) lies on the northwest-southeast axis of a volcanic range that traverses the country. The reddish color (dense vegetation) that surrounds most of the existing volcanic peaks help identify the main axis of the volcanic range, whose elevations average approximately 4000 feet (1200 meters) above sea level. El Salvador has more than 20 volcanoes; some are still active. San Salvador, with a population of more than 1 million, lies west of Lake Lapango and 20 miles (32 kilometers) east-southeast of circular Lake Coatepeque—two old calderas filled with water. The elongated body of water north of San Salvador is the Cerron Grande Reservoir, and a smaller reservoir can be seen on the Lempa River east of San Salvador. A very narrow coastal plain is visible along the Pacific Ocean.