The Devils Marbles are a symbol of the outback in Australia and across the world. Yet the classic photo of two giant rounded boulders in the vast arid landscape hardly does justice to an area that is both much more extensive and spiritually significant than portrayed on most postcards.

Known as Karlu Karlu by aboriginals, many creation “Dreaming” stories of the area take place near the marbles. While some people have asserted that the giant rocks are fossilized eggs of the Rainbow Serpent, this belief is not widely held. Still, the entire area is of great spiritual significance to many in Australia.

Beyond their significance, the Devils Marbles Conservation Area is much larger than most give it credit. Not comprised of only two marbles, the park actually spans 4500 acres of the dry outback, and houses hundreds of rounded rocks. Over millions of years, erosion of sandstone and exposure to the elements caused these granite rocks to take rounded edges, making many fields full of the marbles. Although many have retained a round shape, the process of solarization, or expanding and contracting in the desert’s temperature extremes, has caused some of the marbles to split completely in half.

Some of the rocks are over 20 feet in diameter, while others are smaller than one foot. One of the biggest rocks was taken from the site and dedicated as a memorial to John Flynn, who founded a rural emergency service for the outback. However, since the Devils Marbles area is a sacred site, the move was met with great protest and the rock was returned to its natural habitat.