Uluru is one of Australia's most recognizable natural icons. The world-renowned sandstone formation stands 348 m (1,142 ft) high (863 m/2,831 ft above sea level) with most of its bulk below the ground, and measures 9.4 km (5.8 mi) in circumference.

Uluru is notable for appearing to change colour as the different light strikes it at different times of the day and year, with sunset a particularly remarkable sight when it briefly glows red. Although rainfall is uncommon in this semiarid area, during wet periods the rock acquires a silvery-grey colour, with streaks of black algae forming on the areas that serve as channels for water flow.

*thanks wikipedia