Hierapolis had several baths which exploited the mineral springs: the major ones were located near the sanctuary and near the gate. Next to the gate there was also a large market with porticoes. Frontinus took care of some very natural needs; the men's room between the gate and the market maybe lacked some privacy, but was definitely very imposing.
On the paved road heading back to the southern entrance, notice the crumbling but imposing Roman bath, built around the end of the 2nd century and later converted into a Byzantine basilica. From the looks of several of the archways, one more earthquake and this structure is road dust.