Wandjina art form of contact art found in quartzite sandstone cliffs on Bigge Island, Kimberley, Western Australia, Australia, Pacific

Round House, Chinese: Tulou, with ancestral temple, round adobe building of the Hakka minority, Ta Xia de Yuan Building, Hukeng, Fujian, China, Asia

Roundhouse, Chinese: Tulou, with ancestral temple, adobe round house of the Hakka minority, Ta Xia de Yuan Building, Hukeng, Fujian, China, Asia

A park ranger climbs a ladder to enter the Balcony House cliff dwelling at Mesa Verde National Park, featuring cliff dwellings of ancestral Puebloans that are nearly a thousand years old, Cortez, Colorado, USA

Ancestral gallery, Muenchner Residenz royal palace, home of the Wittelsbach regents until 1918, Munich, Bavaria, Germany, Europe

A park ranger watches as visitors climb a ladder to enter the Balcony House cliff dwelling at Mesa Verde National Park, featuring cliff dwellings of ancestral Puebloans that are nearly a thousand years old, Cortez, Colorado, USA

Visitors tour the Spruce Tree House cliff dwelling at Mesa Verde National Park, featuring cliff dwellings of ancestral Puebloans that are nearly a thousand years old, Cortez, Colorado, USA