A magical and spectacular natural site, unique in the world, Pamukkale (Hierapolis) is a fairyland of dazzling white castles. Thermal spring waters laden with calcareous salts running off the plateau' edge have created this fantastic formation formation of stalactites, cataracts and basins. The hot springs have been used since Roman times for their therapeutic powers. Both the thermal center with its motels and thermal pools as well as the ruins of the ancient city of Hierapolis are situated on the plateau.
Another thermal center northwest of Pamukkale is Karahayit, known for its water's
high-iron content. Honaz Dagi National Park is 20 km east of Denizli, near the town of Honaz.Mt.Honaz is one of the most beautiful and highest peaks (2528m) in the Aegean region. It is covered with a gorgeous alpine forest.
The remains of ancient Colossae, a site of early Christian activity, can be seen on the northern slore.