Sea 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)
blog.robertharding.com 