The surrounding region is a continuation of the valley of Mesopotamia and was formed by the deposition of sediments eroded from the Zagros Mountains. Economically backward, the region is populated by the Posht-e Huhi group of Lurs, many of whom are settled farmers.

There are also a large  Oil fields in the region. A climatological station and a small thermoelectric-power plant are located at Ilam. Pop. (1982 est.) 135.950

By Kamal Najmaddin