Calcium's not just good for bones - the spa town of Pamukkale has built a centuries-long reputation on the stuff. The unique formations of travertine shelves, pools and stalactites, hugging the ridge above town like a white scar, were created by the area's warm mineral water, which cools as it cascades over the cliff edge and deposits its calcium.
The tourist boom of the '80s and '90s had a detrimental effect on the site, as a line of hotels above the travertines drained away the waters, leaving the travertines dry, dull and dirtied. In a drastic attempt to preserve the site, all the hotels have been demolished and visitors can no longer bathe in the pools; however, the flow of water is still very slow, and it may be that the real culprits are the many swimming pools in the village below.
Long before Pamukkale was listed as a World Heritage site, the Romans recognised its appeal and built a large spa city, Hierapolis, to take advantage of the water's curative powers. These days, the extensive ruins of Hierapolis make Pamukkale well worth a visit, whether you paddle the ridges or not.