He rock formations of PAMUKKALE "Cotton Castle" - are perhaps the most visited attraction in this part of Turkey, a series of white terraces saturated with dissolved calcium bicarbonate, bubbling up from the feet of the Cal Dagi Mountains beyond. As the water surges over the edge of the plateau and cools, carbon dioxide is given off and calcium carbonate precipitated as hard chalk or travertine. The spring emerges in what once was the exact middle of the ancient city of Hierapolis, the ruins of which would merit a stop even if they weren't coupled with the natural phenomenon. Sadly, however, the Pammukale travertine is gradually turning from white to yellow and is even thought to be drying up. Thirsty hotels, which have been thrown up to accommodate ever-growing numbers of visitors, have been blamed by the government which has decided to take drastic action. Many of the shops and hotels around the site are being demolished. This is ultimately good news for Pamukkale, but it means finding somewhere to stay is getting harder. Most travellers still stay in PAMUKKALE KOYU, above which the travertine terraces are deservedly the first item on their agenda, although the pools are very shallow and a foot-soak is all that's possible - original water levels are depleted by the diversion of water to pools of nearby hotels. There is talk of closing some of these and stopping tourists walking on the terraces at all. Present restrictions require removal of shoes. The archaeological zone of Hierapolis lies west of Pamukkale Koyu, via a narrow road winding up past the Turism Motel. Its main features include a temple of Apollo and the adjacent Plutonium - the latter a cavern emitting a toxic gas, probably a mixture of sulphur compounds and carbon dioxide, capable of killing man and beast alike. There's also a restored Roman theatre, just east of here, dating from the second century AD and in exceptionally good shape, with most of the stage buildings and their elaborate reliefs intact. Arguably the most interesting part of the city, though, is the colonnaded street which once extended for almost 1km from a gate 400m southeast of the sacred pool, terminating in monumental portals a few paces outside the walls - only the most northerly of which, a triple arch flanked by towers and dedicated to the Emperor Domitian in 84 AD, still stands. Just south of the arch is the elaborate tomb of Flavius Zeuxis - the first of more than a thousand tombs constituting the necropolis, the largest in Asia Minor, extending for nearly 2km along the road. There's also a museum, housed in the restored, second-century AD baths, whose disappointing collection consists of statuary, sarcophagi, masonry fragments and smaller knick-knacks recovered during excavations. We hope your tour was a memorable one and we look forward to seeing you in the future on another TravelShop Booking Tour. Have a safe trip back home and thanks for choosing TravelShop Booking.