Manjanggul Lava Tube, UNESCO World Heritage Site, Jeju Island, South Korea, Asia

Manjanggul Lava Tube, UNESCO World Heritage Site, Jeju Island, South Korea, Asia

Manjanggul Lava Tube, UNESCO World Heritage Site, Jeju Island, South Korea, Asia

Raufarholsheillir lava tube cave system, Iceland, Polar Regions

Lava Tube, Santa Cruz, Galapagos, UNESCO World Heritage Site, Ecuador, South America

Aerial of the Koko Oana underground lava tube, Anaa atoll, Tuamotu archipelago, French Polynesia, South Pacific, Pacific

Manjanggul longest lava tube system in the world on the island of Jejudo, UNESCO World Heritage Site, South Korea, Asia

Manjanggul longest lava tube system in the world on the island of Jejudo, UNESCO World Heritage Site, South Korea, Asia

Manjanggul longest lava tube system in the world on the island of Jejudo, UNESCO World Heritage Site, South Korea, Asia

Manjanggul longest lava tube system in the world on the island of Jejudo, UNESCO World Heritage Site, South Korea, Asia

'The Spouting Horn' on the south coast near Poipu, where sea swell is forced through an old lava tube, making a strange noise, Kauai, Hawaii, USA

Pool in the lava cave ""Jameos del Agua"", designed by Cesar Manrique, Lanzarote, Canary Islands, Spain, Europe

Swimming pool, lava cave Jameos de Aqua, by Cesar Manrique, Lanzarote, Canary Islands, Spain, Europe

Water reflections in the cave Cueva de los Verdes, illuminations of the cave system of a lava tube designed by Cesar Manrique, Lanzarote, Canary Islands, Spain, Europe

Entrance to Thurston Lava Tube, Lava tube, Hawai'i Volcanoes National Park, Big Island, Hawaii

Mackerel Scad (Decapterus Macarellus) Schooled Off The Kona Coast, Kona, Island Of Hawaii, Hawaii, United States Of America

Wire coral goby (Bryaninops yongei) on wire coral (Cirrhipathes sp.), a relative of black coral.

Hawaii, Big Island, Hawaii Volcanoes National Park, Molten lava seen through hole in lava tube.

Australia Western Australia Wagin Wave Rock - Eroded Lava Tube Antipodean Aussie Australian Oceania Oz

Tourists in the lava tunnels, Reunion Island, France