Pamukkale, meaning "cotton castle" in Turkish, is a natural site in Denizli in southwestern Turkey. The area is famous for a carbonate mineral 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 ancient Greco-Roman city of Hierapolis was built on top of the white "castle" which is in total about 2,700 meters (8,860 ft) long, 600 m (1,970 ft) wide and 160 m (525 ft) high. It can be seen from the hills on the opposite side of the valley in the town of Denizli, 20 km away.
Known as Pamukkale (Cotton Castle) or ancient Hierapolis (Holy City), this area has been drawing the weary to its thermal springs since the time of Classical antiquity. The Turkish name refers to the surface of the shimmering, snow-white limestone, shaped over millennia by calcium-rich springs. Dripping slowly down the vast mountainside, mineral-rich waters foam and collect in terraces, spilling over cascades of stalactites into milky pools below. Legend has it that the formations are solidified cotton (the area's principal crop) that giants left out to dry.