Two tile impassable natural wonder. +1 Amenity. It provides an additional Amenity if adjacent to an Entertainment Complex. Major adjacency bonus to Theater Square, Campus, and Commercial Hub districts. Standard adjacency bonus to the Holy Site district. It provides Fresh Water.

The ‘Cotton Castle' in Aegean Turkey may not be quite as soft as its name implies, but the warm spa-quality waters overflowing the white calcite terraces make for quite the spectacular sight. Yet it isn't just modern tourists that recognize the healing and relaxing powers of this place; above the terraces is Hierapolis, the ruins of an ancient Roman spa city. It would seem that the desire to relax in warm water is something that all people have in common.

The creation of this natural site took place slowly over millennia, each year growing ever so slightly. Calcium carbonate in the spring water thickens and ultimately crystallizes after the water reaches the surface, forming the hard travertine deposits that make up the stalactites, terraces, and “clouds” that stretch for more than a mile.