Pamukkale, is Turkey's foremost mineral-bath spa because of its natural beauty: Hot calcium-laden waters spring from the earth and cascade over a cliff. As they cool they form dramatic travertines of hard, brilliantly white calcium that form pools.
Named the Cotton Fortress, it has been a spa since the Romans built the spa city of Hierapolis around a sacred warm-water spring. The Antique Pool is still there, littered with marble columns from the Roman Temple of Apollo. You can swim in it for a fee.
We opted for a one day tour from Bodrum but frankly it was way too crowded than what the pictures look like on the internet. Nevertheless, it is something which one shouldn't miss.