Sassi di Matera, UNESCO World Heritage Site, Basilicata, Italy, Europe

Caleta Negra (Black Bay) a popular boat trip and walk with its distinctive sedimentary and lava strata, Ajuy, Fuerteventura, Spain, Atlantic, Europe

Elephant Cave Temple in the Sacred Monkey Forest Sanctuary, Ubud, Bali, Indonesia, Southeast Asia, Asia

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

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

The Doll House, Ancestral (Anasazi) Pueblo building, 1150-1250 AD, Bears Ears National Monument, Cedar Mesa, Utah, United States of America, North America

Buddha statues in one of the 947 Hpowindaung sandstone caves, 18th century paintings on the walls, Monywa, Sagaing District, Myanmar (Burma), Asia

Target Ruins, Ancestral Pueblo, up to 1000 years old, Coomb Ridge area, Utah, United States of America, North America

Entrance gate to the Goa Gajah temple complex, Bali, Indonesia, Southeast Asia, Asia

Target Ruins, Ancestral Pueblo, up to 1000 years old, Coomb Ridge area, Utah, United States of America, North America

Tower Ruins, Ancestral Pueblo, up to 1000 years old, Coomb Ridge area, Utah, United States of America, North America

Aerial of Sassi di Matera in fog, UNESCO World Heritage Site, Basilicata, Italy, Europe

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

Necropolis, Facade Street, Petra, UNESCO World Heritage Site, Jordan, Middle East

Sassi di Matera, UNESCO World Heritage Site, Basilicata, Italy, Europe

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

Grotto of Buontalenti, Boboli Gardens, Florence, Tuscany, Italy, Europe

Beida (Little Petra), Nabatean site near Petra, Jordan, Middle East

Caglieron caves, Church in a cave, Veneto, Italy, Europe

Floe stone in the main cave at Carlsbad Caverns National Park, UNESCO World Heritage Site, located in the Guadalupe Mountains, New Mexico, United States of America, North America

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

Unconformity of older Jurassic sediments and Pliocene limestone plus later lava on top at Caleta Negra, Ajuy, Fuerteventura, Spain, Atlantic, Europe

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

Tower Ruins, Ancestral Pueblo, up to 1000 years old, Coomb Ridge area, Utah, United States of America, North America

Floe stone in the main cave at Carlsbad Caverns National Park, UNESCO World Heritage Site, located in the Guadalupe Mountains, New Mexico, United States of America, North America

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

Caves carved in the stone of the mountain inside, Petra, UNESCO World Heritage Site, Jordan, Middle East

The caves at Ajanta, Deccan Hills, Maharashtra State, India

Stone carved Buddha and Bodhisattva, Cave No.20, Yun Kang Caves, UNESCO World Heritage Site, China, Asia

Buddha statue in cliffs (since destroyed by the Taliban), Bamiyan, Afghanistan

Looking out through entrance of cave, Deer Cave, Gunung Mulu National Park, UNESCO World Heritage Site, Sarawak, island of Borneo, Malaysia, Southeast Asia, Asia

View from the Alum Cave Bluffs trail in Great Smoky Mountains National Park, UNESCO World Heritage Site, Tennessee, United States of America (U.S.A.), North America

Statue of Mahavira, founder of the Jain religion in the Indra Sabha, Cave 32, in Jain section of the cave temples of Ellora, UNESCO World Heritage Site, Maharashtra, India, Asia

Sof Omar cave, main gallery of River Web, Southern Highlands, Ethiopia, Africa

Shrine guarded by Bodhisattva figures, dating from 7th century, in Cave 5, Ellora, UNESCO World Heritage Site, near Aurangabad, Maharashtra state, India, Asia

Shiva the great ascetic, Kailasa, Ellora, UNESCO World Heritage Site, Maharashtra state, India, Asia

Shiva, destroyer of the elephants, Kailasa, Ellora, UNESCO World Heritage Site, Maharashtra state, India, Asia

Trimurti, Elephanta cave, late Gupta dating from between the 9th and 11th centuries, UNESCO World Heritage Site, Elephanta island off Mumbai, India, Asia

People at Dambulla cave Buddhist temple complex, UNESCO World Heritage Site, Sri Lanka, Asia

Cueva de Los Verdes, cave tourist attraction in lava pipe tunnel, Lanzarote, Canary Islands, Spain, Atlantic, Europe

Royal tomb, Petra, UNESCO World Heritage Site, Jordan, Middle East

Detail of stone carving of the Buddha, Ellora Caves, UNESCO World Heritage Site, Maharashtra state, India, Asia

The Ellora Caves, temples cut into solid rock, UNESCO World Heritage Site, near Aurangabad, Maharashtra, India, Asia

Cave dwellings, near Goreme, Cappadocia, Anatolia, Turkey, Asia Minor, Asia

House in rock, Cappadocia, Anatolia, Turkey, Asia Minor, Asia

Cave dwellings, near Goreme, Cappadocia, Anatolia, Turkey, Asia Minor, Asia

Cave dwellings, near Goreme, Cappadocia, Anatolia, Turkey, Asia Minor, Asia

The Fouguo, an ancient underground tunnel found, Carn Euny, a well preserved Iron Age settlement, near Sancreed, Cornwall, England, United Kingdom, Europe

Natural rock archway carved by the sea through karst limestone rock at Cuevas del mar (sea caves) beach, near Llanes, Asturias, Spain.

Pillar, geological calcareous formation on the wall of Anhumas Abyss, Bonito, Mato Grosso do Sul, Brazil, South America

Zodiacs cruising through the sea caves of Fugloy in the Faroe Islands

diver in the red sea with some red soft coral. Red Sea

Sara Campbell world Champion freediver running freediving courses in Dahab. Egypt.

Sara Campbell world Champion freediver running freediving courses in Dahab. Egypt.

12/04/2009. United Kingdom, City of Gibraltar, St Michalel's Cave, Upper Rock Nature Reserve. Stalactites and lime scale formations on cave roof. . City Of Gibraltar, St Michalel's Cave, Gibraltar Strait . UK, United Kingdom

Sara Campbell world Champion freediver running freediving courses in Dahab. Egypt.

Diver swimming between coral walls

diver in Blue Hole stalactites formations. Belize

12/04/2009. United Kingdom, City of Gibraltar, St Michalel's Cave, Upper Rock Nature Reserve. Stalactites and lime scale formations on cave roof. . City Of Gibraltar, St Michalel's Cave, Gibraltar Strait . UK, United Kingdom

12/04/2009. United Kingdom, City of Gibraltar, St Michalel's Cave, Upper Rock Nature Reserve. Stalactites and lime scale formations on cave roof. . City Of Gibraltar, St Michalel's Cave, Gibraltar Strait . UK, United Kingdom

Hikers exploring rock cave

Hikers standing at entrance of cave

Portrait of Caucasian boy and girls hiking on rocks at beach

Portrait of Caucasian boy and girls hiking on rocks at beach

Rocks framing Golden Gate Bridge, San Francisco, California, United States

Caucasian teenage boy exploring cave

Caucasian teenage boy exploring cave

Cone forest inside the lake, Anhumas Abyss, Bonito, Mato Grosso do Sul, Brazil

Inside Basílica de Santa María la Real de Covadonga catholic church in Cangas de Onis, Picos de Europa, Asturias, Spain, Europe. In 1777 a fire destroyed the old temple, which stood adjacent to the Holy Cave where Our Lady of Covadonga is revered. It was then decided to raise a new church as a monumental sanctuary, raising donations from all of Spain; the plan was opposed by the local council, as the canons wanted to rebuild the temple of the Holy Cave and build an ambitious sanctuary that had once been designed by Ventura Rodríguez, but never completed. One century later, the project was resumed by King Alfonso XII of Spain, who was interested in completing this work. The classic design of Ventura Rodríguez was very difficult and expensive and was replaced by a new neo-Medieval design.

Our Lady of Covadonga. The Blessed Virgin Mary, and a Marian shrine devoted to her at Basílica de Santa María la Real de Covadonga catholic church in Cangas de Onis, Picos de Europa, Asturias, Spain, Europe. In 1777 a fire destroyed the old temple, which stood adjacent to the Holy Cave where Our Lady of Covadonga is revered. It was then decided to raise a new church as a monumental sanctuary, raising donations from all of Spain; the plan was opposed by the local council, as the canons wanted to rebuild the temple of the Holy Cave and build an ambitious sanctuary that had once been designed by Ventura Rodríguez, but never completed. One century later, the project was resumed by King Alfonso XII of Spain, who was interested in completing this work. The classic design of Ventura Rodríguez was very difficult and expensive and was replaced by a new neo-Medieval design.

Niches in wall near Greek Theatre, Neapolis Archaeological Park, Syracuse, Sicily, Italy

Carved Buddha statue, Fengxian Temple, Longmen Grottoes and Caves, Luoyang, Henan Province, China, Tang Dynasty

Prehistoric Man, Stone Age Cave Dweller

New Zealand

View out of the Stone Mirror Cave Goa Batu Cermin, Labuhanbajo, West Flores, Nusa Tenggara, Lesser Sunda Islands, Indonesia, Southeast Asia, Asia

Mining Plant Museum Schacht Knesebeck, UNESCO World heritage site, Bad Grund, Harz, Lower Saxony, Germany

Upper Antelope Canyon, Korkskrew Canyon, Slot Canyon, Arizona, USA

Woman climbing on basalt columns, Halsanefshellir cave, Reynisfjara beach at Vik i Myrdal, South Coast, Iceland, Europe

Man standing in Upper Antelope Canyon near Page, Arizona, USA

Mehely's horseshoe bat (Rhinolophus mehelyi) in a cave, Sardinia island, Italy, Europe

Colourfully, illuminated Hang Sung Sot cave, Surprise Cave, Cave of Awe, a UNESCO World Heritage Site, stalactite cave in Halong Bay, Vietnam, Southeast Asia, Asia

Woman climbing on basalt columns, Halsanefshellir cave, Reynisfjara beach at Vik i Myrdal, South Coast, Iceland, Europe

Cave di Fantiscritti, marble quarry near Carrara, Massa-Carrara Province, Tuscany, Italy, Europe

Batu Caves, limestone caves near Kuala Lumpur, Malaysia, Southeast Asia

Uchisar, Cappadocia, Turkey

Prehistoric arrowheads in a cave, Uyuni Highlands, Bolivia

Prehistoric weapons and tools in a cave, Uyuni Highlands, Bolivia

Meramec Caverns with limestone structures such as stalagmites and stalactites on the Meramec River, Missouri, USA

Meramec Caverns with brightly illuminated limestone structures in the so called Movie Theatre, Missouri, USA

Tomb, lycian burial place in the rocks facing the river delta at Caunos, Dalyan in the district of Mugla, Turkey

Rock dwellings of Uchisar, Cappadocia, Cental Anatolia, Turkey, Asia

Rock dwellings of Uchisar, Cappadocia, Cental Anatolia, Turkey, Asia

Egyptian temple of Debod, 2nd century BC, at dusk, Madrid, Spain, Europe

Predjama Castle, Predjamski Grad, near Postojna, Inner Carniola, Slovenia, Europe

Interior of Ali Sadr Cave, Hamadan, Hamedan, Persia, Iran, Asia

Celtic Hypogeum, also known as Roman jail or Lombard prison, Cividale, Friuli, Italy, Europe

Celtic Hypogeum, also known as Roman jail or Lombard prison, Cividale, Friuli, Italy, Europe

Saalfelder Feengrotten or Saalfeld Fairy Grottoes, Saalfeld, Thuringia, Germany, Europe

Panorama shot of the largest submontane lake in Europe, Lac souterrain de St-Leonard, St-Leonhard Underground Lake, Valais, Switzerland, Europe

Accessible cave with a small waterfall and lake, Grotte aux Fees, Valais, Switzerland, Europe