Pamukkale's terraces are made of travertine, a sedimentary rock deposited by water from the hot springs. 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.
Travertine is a terrestrial sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters, or geothermally heated hot-springs. Similar but softer and extremely porous deposits formed from ambient-temperature water are known as tufa.
Ancient city Hierapolis is a UNESCO World Heritage Site. The hot springs there have been used as a spa since the 2nd century BCE. The former Roman Bath of the ancient city of Hierapolis has been used as the site of the Hierapolis Archaeology Museum since 1984.