Tim Fitzharris / Rock arch, Atuh Beach, Nusa Penida, Bali, Indonesia

Guy Edwardes / Durdle Door by moonlight, Jurassic Coast, Dorset, England, UK. December 2014.

Guy Edwardes / Durdle Door and Bats Head at sunset, Jurassic Coast, Dorset, England, UK. December 2014.

Guy Edwardes / Natural Arch, Siabost, Isle of Lewis, Outer Hebrides, Scotland, UK. March, 2015.

Guy Edwardes / Gaada Stack, Foula, Shetland, Scotland, UK. August, 2014.

Colin Monteath / Coastal cliffs, Tunnel Beach, Otago Peninsula, Otago, New Zealand

Benjamin Barthelemy,Benjamin Barthelemy / Landscape view of the Manneporte, a natural rock arch and needle, Etretat, Normandy, France, June

Sue Daly,Sue Daly / Northern Arch, Poor Knights Islands Nature Reserve, North Island, New Zealand, January 2013

Thomas Lazar / Ice hanging from arch in sea cave carved in soft sandstone cliffs, frozen lake, Squaw Bay, Lake Superior, Apostle Islands National Lakeshore, Wisconsin, USA, February 2009

Angelo Gandolfi / Egyptian vulture (Neophron percnopterus) in flight, with natural rock arch in the background. Canyon del Ebro and Rudron, Castilla y Leon, Spain.

Graham Eaton / The Green Bridge of Wales, a natural rock arch comprising Carboniferous limestone, Castlemartin, Pembrokeshire, Wales. September 2017.

Graham Eaton / The Green Bridge of Wales, a natural rock arch comprising Carboniferous limestone, Castlemartin, Pembrokeshire, Wales. September 2017.