in the whole Sahara. Western Uweinat: Shelters under the huge granite boulders in the western Uweinat contain numerous paintings, including the famous sites of Ain Doua. Jebel Arkenu, Jebel Kissu & Yerguehda Hill, the lesser granite massifs around Uweinat have many smaller sites. Saharan rock art has been found to resemble the art of Nile valleys. The Saharan area was wetter until mid-Holocene or about 4000 BC, when the monsoon retreated southwards, forcing humans to migrate. Some retreated eastward to the Nile valley, taking with them their beliefs and influencing Egyptian art. 20th century exploration The hills of the Gilf Kebir were first seen from a distance by European explorers in 1910 - with W. J. Harding-King in 1910 and 1911, and Ball and Lieutenant Moore in 1918. The high southern part of the plateau was sighted for the first time by Prince Kamal el Dine Hussein in 1925, and on another expedition, in the following year, he fixed the eastern escarpment of the plateau and first realised the true size of the plateau. In 1930 an expedition headed by Ralph Alger Bagnold followed the same route. In the winter of 1930-1, P. A. Clayton surveyed some of the areas. The western side of the Gilf Kebir was explored in 1932 by the Clayton-Almásy Expedition, headed by Sir Robert East Clayton and Count László E. Almásy, and accompanied by Patrick A. Clayton, Squadron Leader H. W. G. J. Penderel, three Arabian car drivers and a cook. The expedition explored the area by Gypsy Moth plane, by car, and on foot. 1933 Patrick Clayton and Ladislaus Almasy discovered the Aqaba-Pass, the only way up Gilf Kebir from the southern plains i.e. from wadi Sura. WWII archeology The plateau was the site for various British logistical operations during the Second World War, and due to the extremely dry conditions and lack of population, remains of this occupation are often found intact. A large airbase, including huge navigation arrows laid out in army petrol cans, can still be seen at the Eight Bells spot in the southeast of Gilf Kebir. It was also the site of the 2007 discovery of a bag that had been lost in the Second World War by a dispatch rider (Alec Ross) of the Long Range Desert Group, part of the British Army. This contained the rider's personal letters and photographs and had been well preserved. Literary setting