In ancient times all religious buildings were built nearby hot or cold water sources. 

Beside religious buildings, some other buildings such as fountains and baths also were built for curing. The numbers of baths, fountains and also churches are evident of the importance of waters in Hierapolis and Christianity. 

The temples were significant trade centers and Hierapolis had many temples that made people confused about which god they would worship before Christianity. 

People in Hierapolis worshiped Apollo as their main God. Beside Apollo, Artemis-the goddess- had been very important too. Local people in Hierapolis had worshiped many other gods and goddesses such as Dionysus, Leto who was the mother of Apollo, Poseidon who was the reason of earthquakes, Pluto who was the god of underworld, Heracles etc. 

Hierapolis means “Holy City” because of its religious importance and also temples together with other religious buildings.

On the other hand it is thought that Hiera was the name of the wife of Telephos. Telephos was the legendary founder of Pergamum so the founder of the city, Eumenes, named here as Hierapolis in honor of Hiera. Women took very significant place through the history of Anatolia therefore their names were used for newly founded cities.

The ancient city of Hierapolis was settled in an area of 1000 x 800 m. Hierapolis had many destructive strong earthquakes and as a result, each earthquake razed the city. (First destructive one in 17 AD, second one in 60 AD, third and last one in 1354)