The cotton castle or Pamukkale is a geological phenomenon near the city of Denzili in the south west region of Turkey, close to the ancient town of Hierapolis.  These gorgeous turquoise pools are created by hot springs depositing calcium carbonate on the steep slopes of the mountain which over time fanned out creating the beautiful white dam walls.  The frozen waterfalls as they are commonly referred to, are continuously growing as the jelly like calcium carbonate hardens and becomes travertine.

The hot springs have been enjoyed by many, from the Hierapolians to the Romans to the present day Turks and according to legend even Cleopatra bathed here.