Hierapolis-Pamukkale, Hot springs in 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, used since the second century BC.
It is recognized as a UNESCO World Heritage Site, attracting millions of tourists every year.
The site is open to visitors but to help preserve it, walking on the terraces is only permitted without shoes.
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 long and 160m high.
Location: Denizli Province
Source: Wikimedia