Wave Rock (Nyungar: Katter Kich) is a natural rock formation that is shaped like a tall breaking ocean wave. The “wave” is about 15 m high and around 110 m long. It forms the north side of a solitary hill, which is known as “Hyden Rock”. This hill, which is a granite inselberg, lies about 3 km east of the small town of Hyden and 296 km east-southeast of Perth, Western Australia.

Wave Rock is a spectacular example of what geomorphologists call a “flared slope”. A flared slope is a concave-upward or -inward bedrock surface that is typically found around the base of inselbergs, bornhardts, and granitic boulders and also on their higher slopes. Flared slopes like Wave Rock are particularly well developed in granitic landforms of southwestern and southern Australia. The flared slopes are argued to have formed by the concentrated chemical weathering around the base of an inselberg by groundwater.

The chemical weathering of the bedrock by groundwater produces a concave-upward or –an inward pocket of deeply weathered, relatively loose, and disaggregated bedrock within the formerly solid bedrock base of an inselberg. When the land surface, which is underlain by deeply weathered bedrock, around an inselberg is lowered by erosion, the pocket of deeply weathered disaggregated bedrock is also removed to produce a flared slope such as Wave Rock. It has also been argued that flared slopes can form during the erosion of slopes of any inselbergs.

Wave Rock has cultural significance to the Ballardong people. Local tribes believed that wave rock was a creation of the Rainbow Serpent, and was created in her wake by dragging her swollen body over the land after she had consumed all of the water in the land. They respected this area as an icon of cultural learning; a moral from this Dreamtime tale was to be remembered for life.

According to Wikipedia