Namondjok (centre) who ate his clan sister, Namarrgon (right) , the Lightning Man and Barrginj his wife (below left) supernatural ancestors at the rock art site at Nourlangie Rock, Kakadu National Park, Northern Territory, Australia

Bet Giorgis, rock cut church, Lalibela, Ethiopia, Africa

Petroglyph near Chetro Ketl, Chaco Culture National Historical Park, UNESCO World Heritage Site, New Mexico, United States of America, North America

Soldier riding a horse petroglyph, Chetro Ketl, Chaco Culture National Historical Park, UNESCO World Heritage Site, New Mexico, United States of America, North America

Petroglyphs near Una Vida, Chaco Culture National Historical Park, UNESCO World Heritage Site, New Mexico, United States of America, North America

Horus statue, Temple of Horus, Edfu, Egypt

Rock engravings close to Twyfelfontein Lodge, Twyfelfontein, Damaraland, Kunene Region, Namibia, Africa

Petroglyphs, Arches National Park, Moab, Utah, United States of America (U.S.A.), North America

Jar Island Indigenous Gwion Gwion art, dated from at least 17500 years ago, Vansittart Bay, Kimberley, Western Australia, Australia, Pacific

Petroglyphs or rock engravings, Twyfelfontein, UNESCO World Heritage Site, Damaraland, Kunene Region, Namibia, Africa

Petroglyphs or rock engravings, Twyfelfontein, UNESCO World Heritage Site, Damaraland, Kunene Region, Namibia, Africa

Petroglyphs or rock engravings, Twyfelfontein, UNESCO World Heritage Site, Damaraland, Kunene Region, Namibia, Africa

Inscription on stone in the Great Court, temple of Baalbek, UNESCO World Heritage Site, Lebanon, Middle East

Petroglyphs or rock engravings, Twyfelfontein, UNESCO World Heritage Site, Damaraland, Kunene Region, Namibia, Africa

Etchings on sandstone, 6000 years old, finest rock art in Africa, Twyfelfontein, Damaraland, Namibia, Africa

Tuareg script (Tifinagh) on stone, rock carvings, Youf Ahakit, Tassili du Hoggar, Wilaya Tamanrasset, Algeria, Sahara, North Africa

Early Islamic rock carvings, Youf Ahakit, Tassili du Hoggar, Wilaya Tamanrasset, Algeria, Sahara, North Africa

Prehistoric rock carving, bull, La Dalle, Tin Tarabine, Tassili du Hoggar, Wilaya Tamanrasset, Algeria, Sahara, North Africa

Rock carving, Crying Cow, Algeria, Africa

Neolithic rock art, giraffe engraving, of the Tadrart, Tassili n'Ajjer National Park, Unesco World Heritage Site, Algeria, Sahara, North Africa

Neolithic rock art, elephant engraving, of the Tadrart, Tassili n'Ajjer National Park, Unesco World Heritage Site, Algeria, Sahara, North Africa

Aboriginal rock etching, waterhole symbol at Uluru, Uluru National Park, Northern Territory, Australia

Historic stone etchings, petroglyphes, about 4000 years old, Atlatl Rock, Valley of Fire State Park, Nevada, USA

Historic stone etchings, petroglyphes, about 4000 years old, Atlatl Rock, Valley of Fire State Park, Nevada, USA

Carved stones, inner yard, Kyichu Lhakahang, Bhutan, Asia

Carved stones, inner yard, Kyichu Lhakahang, Bhutan, Asia

The White Lady rock painting, Brandberg Mountain, Damaraland; Kunene Region, Namibia

The White Lady rock painting, Brandberg Mountain, Damaraland; Kunene Region, Namibia

Twyfelfontein, an ancient rock engravings site in Damaraland; Kunene Region, Namibia

Twyfelfontein, an ancient rock engravings site in Damaraland; Kunene Region, Namibia

Twyfelfontein, an ancient rock engravings site in Damaraland; Kunene Region, Namibia