The Sentury Rocks are gigantic sized boulders inside of Shuulgar Valley which also contains Black Gazza and Niwob. They are, on average, over a mile high and 4 miles in diameter. They are believed to be ejecta that came from an eruption of Uryysver, a large active volcano in the northeast corner of the valley. The eruption is believed to have deposited these large rocks 50,000 years ago (by local standard time) in a mammoth eruption that sent these solid structures of rock flying and landing in all directions around the planet of Arpaio.
Several villages and hamlets have set up camp underneath these rocks. Many natives believe that these rocks have spiritual and special meaning.