Ajanta Cave complex, Buddhist Temples carved into solid rock dating from the 5th Century BC, Ajanta, Maharastra, India

The Ellora Caves, temples cut into solid rock, near Aurangabad, Maharashtra, India

Corridor off which are monks' living quarters, Cave 2 of Buddhist caves in rock-carved stupa-monastery complex dating from the Kushano-Sasanian period, Takht-I-Rustam (Rustam's Throne), near Haibak, Samangan Province, Afghanistan, Asia

Corridor off which monks' living quarters were carved in cave 2, Takht-I-Rusam (Rustam's throne), part of a Buddhist stupa-monastery complex dating from the Kushano-Sasanian period 4th-5th century AD, Samangan Province, Afghanistan, Asia

Corridor off which monks' living quarters were carved in cave 2, Takht-I-Rusam (Rustam's throne), part of a Buddhist stupa-monastery complex dating from the Kushano-Sasanian period 4th-5th century AD, Samangan Province, Afghanistan, Asia

Troglodyte cave dwellings Guadix

Venetsa Cave in Bulgaria. Beautiful colorful and illuminated cave full with semiprecious onyx stones. Flowstones, stalactites and stalagmites lighted in different vivid colours

Venetsa Cave in Bulgaria. Beautiful colorful and illuminated cave full with semiprecious onyx stones. Flowstones, stalactites and stalagmites lighted in different vivid colours

Monastery church of Panagia Agrilia, abandoned cave dwellings in erosion valley, panoramic view, island of Thirassia, archipelago of Santorini, Cyclades, Greece

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

Uchisar Castle hill, Cappadocia, Turkey

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

A pit house, part of an excavated ancient Anasazi village at the Anasazi State Park Museum, the site dates to the 12th century, Boulder, Utah, USA

Historic habitation and cult site of the Ancestral Puebloans, Cliff Palace, partial view with 3 round ceremonial rooms, so-called called Kivas, about 1200 AD, Mesa Verde National Park, Colorado, USA

Historic habitation and cult site of the Ancestral Puebloans, Cliff Palace, partial view with 2 round ceremonial rooms, so-called called Kivas, about 1200 AD, Mesa Verde National Park, Colorado, USA

Rocky landscape with ancient rock structures under a clear blue sky in Cappadocia, aerial view, Uchisar Castle, Uçhisar Kalesi, impressive rock formation and fortress, Göreme National Park, Göreme Tarihî Millî, Nevsehir Province, Nevşehir, Cappadocia, Cappadocia, Kapadokya, Cappadocia, Central Anatolia, Turkey

Cosy cave dwelling with rustic style and furniture, surrounded by plants and rocky surroundings, aerial view, inhabited monk caves, cave town, cave monastery, Vardzia, Vardzia, Samtskhe-Javakheti region, Samtske Javakheti, Lesser Caucasus, Georgia

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

Shepherd's cabin, Lychnostatis Open Air Museum, Museum of the traditional Cretan life, Hersonissos, Crete, Greece, Europe

Uchisar Castle hill, Cappadocia, Turkey

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

Tuff rock from Uchisar, near by Goereme, Cappadocia, turkey

David Gareja Monastery Complex (The 6th Century Rock-Hewn Georgian Orthodox Monastery With Hundreds Of Cave Cells, Churches, Chapels, Refectories And Living Quarters), Kakheti, Georgia