Pamukkale , Turkey

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

The ancient Greco-Roman and Byzantine city of Hierapolis was built on top of the white "castle" which is in total about 2,700 metres (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.

Tourism is and has been a major industry. People have bathed in its pools for thousands of years. As recently as the mid-20th century, hotels were built over the ruins of Hierapolis, causing considerable damage. An approach road was built from the valley over the terraces, and motor bikes were allowed to go up and down the slopes. When the area was declared a World Heritage Site, the hotels were demolished and the road removed and replaced with artificial pools. Wearing shoes in the water is prohibited to protect the deposits.

Pamukkale is a tourist attraction. It is recognized as a World Heritage Site together with Hierapolis. Hierapolis-Pamukkale was made a World Heritage Site in 1988.

The underground volcanic activity which causes the hot springs also forced carbon dioxide into a cave, which was called the Plutonium meaning place of the god, Pluto. This cave was used for religious purposes by priests of Cybele, who found ways to appear immune to the suffocating gas.

Tadpoles can be found in the pools.