Waters in the terraces are the sediments of the springs with calcium bicarbonate in 33C. Waters, containing mainly calcium salts and carbon-dioxide, run off the plateau's by depositing calcium while carbon-dioxide disappearing. The marvelous landscape of Pamukkale has been created by this gradual formation, leaving a cotton-like image. Located above the theatre of Hierapolis, the mineral water sources from the thermal springs of Cal Mountain. It is collected in a pool, known as the "Sacred Pool" of ancient times, where you can swim amidst the historical remains of Hierapolis. The Sacred Pool is now located inside Pamukkale Hotel.