Uluru is sacred to the Pitjantjatjara Anangu, the Aboriginal people of the area.

[From Wiki]:

Uluru is one of Australia’s most recognisable natural landmarks. The sandstone formation stands 348 m high, rising 863 m above sea level with most of its bulk lying underground, and has a total circumference of 9.4 km. Both Uluru and the nearby Kata Tjuta formation have great cultural significance for the Aṉangu people, the traditional inhabitants of the area.