A sort of underground Pamukkale, this cave gushes with calcium- and sulphur-rich water. The flow, into a large sinkhole, creates a bright white pyramid with warm travertine pools below. Bathing is allowed in the non-aesthetic outside pool. Kaklık Mağarasi is 35km from Pamukkale. Visiting on a tour from Pamukkale is easier than public transport, but the frequent dolmuşes and buses heading east from Denizli on the highway can drop you in Kaklık village (₺6), 4km south of the cave.
A sign points the way from the village; the walk is along a shadeless road. En route to the cave from Pamukkale, you'll pass Ak Han, a well-preserved Seljuk caravanserai (c 1251) with a beautifully carved gateway.