I think there are several in Olu at various hotels.

We had just a Turkish bath at the Dorian Hotel-£5 each. Massages were extra starting at about 20-30 lira for a basic 20 minute massage, up to about 80-100 lira depending on what you wanted and what oils were used.

It was very friendly and clean with both male and female staff and we would recommend it.

We talked to some people who had been to the one at the Lycian Dreams hotel (think its called Pashas) and they said that was also good.

the Turkish baths at the belcekiz beach hotel are supposed to be the best . Not sure of the price though . Turn left at the junction of the main strip/beach front and the entrance is about 50 yds