Tourists visit the Pamukkale in Turkey on June 16, 2013. Pamukkale, meaning "cotton castle" in Turkish, is a natural site in Denizli Province in southwestern Turkey. The city contains hot springs and travertines, terraces of carbonate minerals left by the flowing water. It is located in Turkey's Inner Aegean region, in the River Menderes valley, which has a temperate climate for most of the year. The white "castle" is in total about 2,700 metres long, 600 metres wide and 160 metres high. It is recognized as a World Heritage Site together with Hierapolis in 1988. (Xinhua/Lu Zhe)