Chott Melrhir (Arabic: شط ملغيغ‎) also known as Chott Melghir or Chott Melhir is an endorheic salt lake in northeastern Algeria. It the westernmost part of a series of depressions, which extend from the Gulf of Gabès into the Sahara. They were created between Miocene and Early Pleistocene as a result of compression accompanying the formation of the Atlas Mountains. With the maximum area of about 6,700 km² (2,600 sq mi), Chott Melrhir is the largest lake in Algeria. It lies almost entirely below the sea level, and the lowest point of Algeria, at −40 meters (−130 feet), is located near the middle of the lake. Its size varies over the year and is usually larger than 130 km (81 mi) from east to west.