Wave Rock

The curve was carved underground before the rock was ever exposed

Wave Rock looks like a tall ocean wave caught at the instant before it breaks: a curved wall of granite about 15 metres high and 110 metres long, though the Australian Heritage Database measured its northern face at about 12 metres. It forms the north side of Hyden Rock, a solitary hill about 3 km east of the small Wheatbelt town of Hyden and 296 km east-southeast of Perth, inside the 160 ha Hyden Wildlife Park. More than 100,000 tourists come every year.

The Ballardong people call it Katter Kich. Local tribes held that the Rainbow Serpent made it, dragging her swollen body over the land after she had drunk up all its water, and the rock was respected as a place of learning, its Dreamtime story carrying a moral to be kept for life. It lies on a dreaming trail that runs from the south coast near Augusta to the Great Victoria Desert in the north east, passing Mulka's Cave, Puntapin Rock, Jilakin Rock, Jitarning Rock and Dumbleyung Lake.

Hyden Rock is a granite inselberg of three domes, made of 2.63 billion year-old monzogranite of the Yilgarn Craton. In the Cretaceous, between 100 and 130 million years ago, weathering rotted the granite beneath a lateritised land surface to different depths, depending on how closely it was jointed, leaving buried domes of solid rock wrapped in loose, weathered granite. After Australia parted from Antarctica and the southwest tilted, erosion stripped the weathered rock away and exposed the domes. Wave Rock is what geomorphologists call a flared slope, a concave bedrock surface around the base of an inselberg, and these are especially well developed in the granites of southern and south-western Australia. Groundwater gathered at the foot of the dome and weathered a curved pocket into it while it was still underground; when the land around was lowered, the pocket's loose rock went too, and the curve was left in the open.

In December 1928 the Public Works Department built a wall about halfway up Hyden Rock, following the contours, to funnel rainwater into a storage dam for the settlers of East Karlgarin District, and it was renovated in 1951 to hold more water for Hyden. The Noongar guide Michael Ward has said the rock was lighter, yellow or cream, in the wall's early days, and the water it sends down has helped turn the face red and orange, streaked with black. Nearby are Hippos Yawn and The Humps, and since 2006 the Wave Rock Weekender has brought a music festival out to the rock every year.