No one knows quite how they were formed but they are amazing. The fun bit was that you didn't just get to look over the top of them from a lookout, but you were able to drive through the desurt of them. This was fun.
They had a sign at the entrance to the national park saying that we were not allowed to bring the campervan in so we left it at the entrance. As it happened it would have been fine to bring it in all the way to the interpretive center (Amazing they don't seem to be calling them 'Visitors Center' now they seem to be calling them 'Interpretive Center').