Robert HardingSea arches are made by coastal erosion. Some form when waves become focussed on one piece of rock and others are made when waves attack a part of the cliffs that is weaker than the rest, wearing through to form a tunnel and eventually an arch. Here are some of our favourite pictures of natural sea arches around the world.
Famous sea arch, the Azure Window, Gozo, Malta, Mediterranean (Michael Runkel/Robert Harding)
Morocco, Beach and red cliff of Legzira, Around Sidi Ifni, Atlantic coast (age fotostock/Robert Harding)
A colourful sunset over Durdle Door on the Jurassic Coast, UNESCO World Heritage Site, Dorset, England (Julian Elliott/Robert Harding)
Bowfiddle Rock Arch, spectacular natural arch near Portknockie, Morayshire, Scotland (Patrick Dieudonne/Robert Harding)
Natural Bridges State Park, Santa Cruz, California, United States of America (Richard Cummins/Robert Harding)
Lands End rock formation, Los Cabos, Baja California, Mexico, North America (Michael Runkel/Robert Harding)
Archway Islands, New Zealand (age fotostock/Robert Harding)
Group of horse riders on Wharariki beach with the Archway island behind Farewell spit, Golden Bay (age fotostock/Robert Harding)
Archway Islands Wharariki near Cape Farewell Nelson Province New Zealand (age fotostock/Robert Harding)
Playa de las Catedrales, Ribadeo, Lugo province, Galicia, Spain (age fotostock/Robert Harding)
Porte d’Aval, Etretat, Seine-Maritime, Haute-Normandie, France (age fotostock/Robert Harding)
The stone arch Roque de la Bonanza, El Hierro, Canary Island, Spain (age fotostock/Robert Harding)
Sea arch at Flamborough Head, East Yorkshire, England (Lizzie Shepherd/Robert Harding)
Sea stacks and sea arch on the North East coast at Whitburn between Newcastle and Sunderland, Tyne and Wear, England (Ashley Cooper/Robert Harding)
Underwater photo of Anacapa arch and kelp, Channel Islands National Park, California, USA (Antonio Busiello/Robert Harding)
See more photos of natural sea arches here