Located in Hayden, a lazy 350km due East of Perth in Western Australia, the Hyden Tourism Development Company claims Wave Rock is "...one of Australia's most famous landforms...".
All hyperbole aside, Wave Rock is an impressive landform. It is a 15 metre high, 110 metre long granite cliff with a rounded shape caused by weathering and water erosion which has undercut the base and left a rounded overhang. The overall effect is that of a giant surf wave of granite, preparing to break onto the bush below.
Seeing as you've gone all that way to look at a large rock (along with 10,000 other tourists annually) -- Hyden Tourism suggest you may want to check out the Aboriginal hand prints in the cave of Mulka, tour the salt lakes, and drive to the Rabbit Proof Fence while you're there.
If checking out 2,700 million year old landforms is your bag, then definitely check it out -- or if you happen to be travelling in the vicinity (perhaps on your way to Kalgoorlie), it's worth a look.
Similarly ancient sites in Western Australia include the Bungle Bungles and The Pinnacles -- the latter of which is a slightly more reasonable 250km (3hrs) North of Perth.