Uluru, also referred to as Ayers Rock, is a large sandstone rock formation in the southern part of the Northern Territory, central Australia. It lies 335 km (208 mi) south west of the nearest large town, Alice Springs; 450 km (280 mi) by road. Uluru is sacred to the Pitjantjatjara and Yankunytjatjara, the Aboriginal people of the area. It has many springs, waterholes, rock caves and ancient paintings. Uluru is listed as a World Heritage Site. Uluru is one of Australia’s most recognisable natural icons. Itstands 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. Both Uluru and Kata Tjuta have great cultural significance for the Aṉangu Traditional landowners, who led walking tours to inform visitors about the local flora and fauna, bush foods and the Aboriginal dreamtime stories of the area. 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.