information:filtering, structural:summarization
Libyan Desert

The Libyan Desert, which covers most of Libya, is one of the most arid and sun-baked places on earth. In places, decades may pass without seeing any rainfall at all, and even in the highlands rainfall seldom happens, once every 5–10 years. At Uweinat, as of 2006 the last recorded rainfall was in September 1998.

Likewise, the temperature in the Libyan Desert can be extreme; on 13 September 1922, the town of 'Aziziya, which is located southwest of Tripoli, recorded an air temperature of 58 °C (136.4 °F), considered to be a world record. In September 2012, however, the world record figure of 58 °C was determined to be invalid by the World Meteorological Organization.

There are a few scattered uninhabited small oases, usually linked to the major depressions, where water can be found by digging to a few feet in depth. In the west there is a widely dispersed group of oases in unconnected shallow depressions, the Kufra group, consisting of Tazerbo, Rebianae and Kufra. Aside from the scarps, the general flatness is only interrupted by a series of plateaus and massifs near the centre of the Libyan Desert, around the convergence of the Egyptian-Sudanese-Libyan borders.

Slightly further to the south are the massifs of Arkenu, Uweinat, and Kissu. These granite mountains are ancient, having formed long before the sandstones surrounding them. Arkenu and Western Uweinat are ring complexes very similar to those in the Aïr Mountains. Eastern Uweinat (the highest point in the Libyan Desert) is a raised sandstone plateau adjacent to the granite part further west.

The plain to the north of Uweinat is dotted with eroded volcanic features. With the discovery of oil in the 1950s also came the discovery of a massive aquifer underneath much of Libya. The water in the Nubian Sandstone Aquifer System pre-dates the last Ice ages and the Sahara Desert itself. This area also contains the Arkenu structures, which were once thought to be two impact craters.