The old Lycian port of Phaselis, about 60 kilometers southwest of Antalya, is where Alexander the Great set up his winter quarters in 334 BC. There are remains of a theater, aqueduct, temples, a colonnaded street, and a Hadrian's Arch Gate erected in AD 114.
The seaside location of the ruins is very pretty, and a museum on-site displays excavated finds.
If you have time, a couple of kilometers before Phaselis is the Olympos Teleferik (cable car), which journeys up the side of Tahtali Mountain to the summit at 2,275 meters for panoramic vistas over the coast.