Another wide and deep crater, Doon Kidimi (also known as Petit Trou or Doon Kinimi), lies northeast of Trou au Natron; it is among the most pristine volcanic features in the region. Additional volcanoes in the neighbourhood are the high Ehi Timi northeast and the high Ehi Sosso/Ehi Soso east of Toussidé, the former of which features lava domes. The river Enneri Oudingueur originates closely in the area and becomes a tributary of the Enneri Bardagué, which drains the Tibesti northward.