The darker, north-south oriented landforms are vegetated mountain ridges, where the maximum elevations exceed 8000 feet (2440 meters) above sea level. The lighter-colored landscape shows the location of the valleys that are interspersed throughout this region of east central Yunnan Province. Four lakes, (two lakes are light in color, while two lakes are dark in color) that are aligned north to south, are located in geologically faulted valleys. The largest lake (light-colored feature slightly below center of image) is Lake Dian. Lake Dian is approximately 25 miles (40 km) in length and covers roughly 116 square miles (300 sq km) in surface area. The capital of Yunnan Province, Kunming (population of the metropolitan area is estimated to 3.5 million people) is visible at the north end of Lake Dian (near bottom left). The capital city sits on a plateau that is about 6300 feet (1920 m) above sea level. Extensive areas of karst topography, immediately east of the four lakes, have created unique landforms that are a favorite tourist attraction.