Petroglyphs on a rock depicting a palm tree, Najran Province, Abar Himma, Saudi Arabia

Rock carvings depicting elephant pooing, Tassili N'Ajjer National Park, Tadrart Rouge, Algeria

Rock carvings depicting a warrior with giraffes, Tassili N'Ajjer National Park, Tadrart Rouge, Algeria

Tuareg near a rock carvings depicting giraffes, Tassili N'Ajjer National Park, Tadrart Rouge, Algeria

Rock painting depicting cows, Tassili N'Ajjer National Park, Tadrart Rouge, Algeria

Tourists in front of Jabal Al-Mawaqi giant camel rock art, Najran Province, Thar, Saudi Arabia

Saudi man in front of petroglyphs on a rock depicting hunters riding horses, Najran Province, Thar, Saudi Arabia

Saudi man in front off petroglyphs on a rock depicting ibex, Najran Province, Thar, Saudi Arabia

Petroglyphs carved in a cave, Malampa Province, Malekula Island, Vanuatu

Ancient rock art, Turkana lake, Loiyangalani, Kenya

Petroglyphs on a rock depicting an ibex, Najran Province, Abar Himma, Saudi Arabia

Rock carving in Tchitundo Hulo hills, Namibe Province, Capolopopo, Angola

Petroglyphs on a rock depicting men hunting on horses, Najran Province, Minshaf, Saudi Arabia

Petroglyphs of Aliya the goddess of fertility, Najran Province, Thar, Saudi Arabia

Tourist standing in front of a life-sized camel petroglyph on a rock, Najran Province, Thar, Saudi Arabia

Laas Geel Rock Art Caves, Paintings Depicting Cows And Human Beings, Hargeisa, Somaliland

Laas Geel Rock Art Caves, Paintings Depicting Cows, Hargeisa, Somaliland