Twelve Apostles, South Australia 

The Twelve Apostles is a popular tourist attraction located along the Great Ocean Road in Victoria, Australia, not in South Australia. I apologize for any confusion caused by my previous response.

The Twelve Apostles are a collection of limestone stacks that rise majestically from the Southern Ocean. They are one of the most iconic landmarks in Australia and a significant highlight of the Great Ocean Road drive. Originally, there were twelve limestone formations, hence the name "Twelve Apostles." However, due to natural erosion over time, several stacks have collapsed, and currently, only eight remain standing.

These limestone stacks were formed through the process of erosion, as the harsh winds and relentless waves eroded the soft limestone cliffs, gradually forming caves, arches, and then stacks. The Twelve Apostles are a stunning example of the forces of nature at work and attract millions of visitors each year.

Visitors can explore the Twelve Apostles from various viewing platforms along the coast. There are also helicopter rides available for a bird's-eye view of this breathtaking coastline. The area offers stunning vistas, especially during sunrise and sunset when the golden light enhances the natural beauty of the limestone formations.

While the Twelve Apostles are not located in South Australia, South Australia itself has many other notable attractions, including the picturesque city of Adelaide, the wine regions of Barossa Valley and McLaren Vale, Kangaroo Island, Flinders Ranges, and the famous Nullarbor Plain, among others.