The area of Gebel El-Mokattam, especially the upper plateau is affected by some non-tectonic structures, such as rock displacement and rockfalls. Detailed field study by many investigators indicated that a zone of about 50 meters wide from the edge of upper plateau in a certain places have been deteriorating during the past 25 years. The lithology of the upper plateau consists of jointed limestone blocks, 12 to 15 m high resting upon a layer of claystone, 5 m thick.