(photo courtesy of Alaskan Dude)

Pamukkale, meaning Cotton Castle in Turkish, is a very unique natural sight in South-Western Turkey. 

The site contains a museum, hot springs, and the Cotton Castle, which consists of travertines, which are sedimentary rocks formed by the deposits of carbonate minerals from hot springs. 

The castle is 2,700 metres in length, and roughly 160 metres tall, so large that it can be seen from the town of Denizli, 20km in the distance. 

People have been bathing in the pools here for thousands of years. The ancient city of Hierapolis was built on top of the white castle, which together with the cotton castle, comprises a UNESCO World Heritage site. There is also a Hieropolis Archeology Museum at the site, which was built in 1984. 

There are only two other sites in the world that resemble the cotton castle; Huanglong in western China, and Mammoth Hot Springs in the U.S.