The Twelve Apostles is a collection of limestone stacks off the shore of 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. Seven of the original eight stacks remain standing at the Twelve Apostles viewpoint, after one collapsed in July 2005. Though the view from the promontory by the Twelve Apostles never included twelve stacks, additional stacks—not considered part of the Apostles group—are located to the west within the national park.
The Twelve Apostles were formed by erosion. The harsh and extreme weather conditions from the Southern Ocean gradually erode the soft limestone to form caves in the cliffs, which then become arches that eventually collapse, leaving rock stacks up to 50 meter high. The stacks are susceptible to further erosion from waves. In July 2005, a 50 meter tall stack collapsed, leaving seven standing at the Twelve Apostles viewpoint. Due to wave action eroding the cliffs, existing headlands are expected to become new limestone stacks in the future.
The stacks were originally known as the Pinnacles, and the Sow and Pigs (or Sow and Piglets, with Muttonbird Island being the Sow and the smaller rock stacks being the Piglets), as well as the Twelve Apostles. The formation’s name was made official as the Twelve Apostles, despite only ever having had eight stacks.
In 2002, the Port Campbell Professional Fishermens Association attempted to block the creation of the Twelve Apostles Marine National Park at the Twelve Apostles site. The association approved of a later decision by the Victorian government to prohibit seismic exploration at the site by Benaris Energy, believing such exploration would harm marine life.