I love a good mystery dont you? Whilst i was researching the Great Ocean Road 3 day tour from Adelaide to Melbourne I stumbled across this entry in wikipedia.
The apostles were formed by erosion: the harsh and extreme weather conditions from the Southern Ocean gradually eroded the soft limestone to form caves in the cliffs, which then became arches, which in turn collapsed; leaving rock stacks up to 45 metres high. The site was known as the Sow and Piglets until 1922 (Muttonbird Island, near Loch Ard Gorge, was the Sow, and the smaller rock stacks were the Piglets); after which it was renamed to The Apostles for tourism purposes. The formation eventually became known as the Twelve Apostles, despite only ever having nine stacks.
Interestingly the name was changed to the Apostles , “Why would you?” comes to mind. This is just one of the unususl facts that are ready to be discovered when you travel along the Great Ocean Road.