Kalbarri National Park
The cliffs with “pipe rock” formations in Rainbow Valley along the Mushroom Rock Nature Trail. These are fossilised burrows created by ancient worm-like organisms known as Skolithos. They lived in a shallow, sandy marine environment and the burrows, used for feeding and escaping from waves, probably took minutes to hours to build.
Photo by Ludo Kuipers, Fri Jun 02, 2023