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 the River Menderes valley, which has a temperate climate for most of the year.

Denizli Province is a province and metropolitan municipality of Turkey in Western Anatolia, on high ground above the Aegean coast. Neighbouring provinces are Uşak to the north, Burdur, Isparta, Afyon to the east, Aydın, Manisa to the west and Muğla to the south. It is located between the coordinates 28° 30’ and 29° 30’ E and 37° 12’ and 38° 12’ N. Its area is 12,134 km2, and its population is 1,056,332 (2022). The provincial capital is the city of Denizli.