We went to Pamakkale in 1997. Even then environmental groups were becoming concerned about tourists being able to walk all over the "white" slopes in their shoes discolouring them a dirty yellow, and the three hotels on the crest that "stole" much of the mineral-rich water for their own use so preventing the slopes from regenerating.
I hope someone can tell me this situation has changed now so that it looks like the "cotton castle" in the postcards - but not, then, in reality.