12 Apostles - Walking to the edge
The Twelve Apostles is a collection of limestone stacks off the shore of the Port Campbell National Park, by the Great Ocean Road in Victoria, Australia.
Their proximity to one another has made the site a popular tourist attraction.
The stacks have been formed by erosion, and are all different heights and thicknesses. A number have fallen over entirely as waves continually erode their bases.
A 50-metre tall Apostle collapsed on July 3, 2005. Although it was initially thought that one of the Twelve Apostles fell on September 25, 2009 it was later revealed that it was one of the smaller stacks knowns as The Three Sisters.
Other well-known features in Port Campbell National Park created by erosion are the London Arch, Loch Ard Gorge and the Island Archway.
The rate of erosion at the base of the limestone pillars is approximately 2 cm per year.