Former Island Archway, now two massive Sandstone Stacks that glow gold in the sun
With the archway existing or not, the huge stacks of Sandstone & Limestone are incredible to see and from so close. The top of the former Island Arch is around 50 metres above the sea level, which is about the same height as most of the 12 Apostles.
If you’re to walk just 100 metres or so to the east of the Island Arch, you’ll be able to look over the Razorback to see 3 of the Apostles you couldn’t see from Castle Rock at the main Apostles viewing area.
The best view of the Island Arch is from the Tom & Eva Lookout
The Island Arch is just near the Loch Ard Gorge car park, which is less than a 5 minute drive from the Apostles.
Online, it’ll tell you to head out to the ‘Island Arch Lookout’ which doesn’t actually exist anymore and hasn’t for some time. If you’re to walk out to that lookout, you’ll instead go out to view Mutton Bird Island at the entrance of Loch Ard Gorge on the Shipwreck Walk.
The best place to get a view of the two huge stone stacks is to walk from the Loch Ard Gorge car park to the Razorback, then about 150 metres into the walk, you’ll get to the Tome & Eva Lookout which gives you a direct view of the former Island Arch.
How the Island Arch formed & why it collapsed
Much the same as the entire Port Campbell National Park on the Shipwreck Coast, even over hundred kilometers to the east along the Surf Coast, back towards Torquay near the start of the Great Ocean Road or hundreds of kilometres to the west in South Australia on the Limestone Coast, this entire area was once at the bottom of deep ocean.
Over millions of years, fish and plants died, rivers dragged sand into the ocean and it all compacted at the bottom of the water under huge amounts of pressure. The sedimentary rock that was created is known a Sandstone and if it’s made up of 50% or more of chalk fossils, then that bit of Sandstone is Limestone.
The ocean eventually retreated and has been eroding the coastline ever since. Around 6,000 years ago, after the last Ice Age the current water level was reached, although for as long as the water has been smashing against these cliffs, it’s eroded the stone at a rate of about 1.5-2cms per year. Some parts of the stone will erode faster, this causes caves and tunnels. Over a lot of time, the tunnels will create huge gorges and if the ceiling falls out on most but not all of the tunnel, an arch way is created. If the arch way is turned into an island from the surrounding land eroding away, you’ll get left with a huge stack, just like the current Island ‘Arch’ or the 12 Apostles.
To see a huge arch way that’s still standing, head further west along the Great Ocean Road for about 15 minutes and head to London Arch, just past the town of Port Campbell. While you’re there, head over to The Grotto which is a nearby formation in the Sandstone also caused by erosion, but totally different to anything else you’ll see in the area.