Hisaronu and Oludeniz
Oludeniz is billed as the Blue Lagoon, where they filmed the unwatchable movie, but it translaets as Dead Lagoon - it is hidden by a promontory and calm as a duck pond.
The town of Hisaronu is up the hill past mount Babadag (can't do the accentuated silent 'g' which elongates the previously vowel - so you promunce Babadag 'Babadaa"). It runs into the resort of Ovacik then drops down the other side of the hill to the port of Fethiye.
Currently 60 minutes by car or coach from Dalaman airport, there is a tunnel going through the mountain - which will half the journey time - but at risk of turning the whole place into another anonymous sunpot with the local identity subsumed by visitors