Uluṟu is an sandstone inselberg, rising above the plains around it. Most of its bulk is below the ground. Kata Tjuṯa, west of Uluṟu, is a group of 36 rock domes (or bornhardts), divided by steep-sided valleys. It covers an area of . The tallest dome, Mount Olga, is above the surrounding plain. It is the highest point in the park, at above sea level.