The Danakil Desert is a desert in northeast Ethiopia, southern Eritrea, and northwestern Djibouti. Situated in the Afar Triangle, it stretches across 100,000 square kilometres (10,000,000 ha) of arid terrain. The area is known for its volcanoes and extreme heat, with daytime temperatures surpassing 50 °C (122 °F). It is inhabited by a few Afar, who engage in salt mining. Local geology is characterized by volcanic and tectonic activity, various climate cycles, and discontinuous erosion. The Danakil desert has a number lakes formed by lava flows that dammed up several valleys. Among these is Lake Afrera, which has thick saline crusts on its banks. The area is flanked toward the east by the Dancal Alps, a tabular mountain system that has a few volcanic cones which peak in height in Mount Ramlo (2,130 metres (6,990 ft)). A plinth of salt up to 800 metres (2,600 ft) thick can also be found in the Salt Plain flatlands. Other local lakes include Lake Asale (116 metres (381 ft) below sea level) and Lake Giuletti/Afrera (80 metres (260 ft) below sea level), both of which possess cryptodepressions in the Danakil Depression. The Afrera contains many active volcanoes, including the Maraho, Dabbahu, Afdera and Erta Ale.