Pamukkale, meaning “cotton castle” in Turkish, is a natural site in Denizli Province in southwestern Turkey. The area is famous for a carbonate mineral left by the flowing of thermal spring water. It is located in Turkey’s Inner Aegean region, in river Menderes valley, which has a temperate climate for most of the year. The ancient Greek city of Hierapolis was built on top of the travertine formation. Pamukkale city was added as a UNESCO World Heritage Site in 1988 along with Hierapolis.