A sandstone boulder sculpted by wind abrasion, Wadi al-Hitan

A boulder at Wadi al-Hitan sculpted by wind erosion (aeolian processes). Whale Valley (Wadi al-Hitan) - a UNESCO World Heritage Site, Sahara, Egypt. The place is known for its great number of fossils, particularly those of the early forms of whales called Archaeoceti, the mammals which lived here in Eocene. That makes Wadi al-Hitan a very significant site documenting the evolution.