Antiphellos was a small settlement and the port for Phellos, the much larger Lycian town further north in the hills. Its small Hellenistic theatre, 500m west of the main square, could seat 4000 spectators and is in very good condition. You can also walk to the rock tombs cut into the sheer cliffs above town, which are illuminated at night. The walk is strenuous so go at a cool time of day.
Walk up hilly Uzun Çarşı Sokak, the Roman-era road that locals call Slippery St, to the east of the main square to reach the King's Tomb, a superb example of a 4th-century BC Lycian sarcophagus. It's mounted on a high base and has two lions' heads on the lid.