The ruins of the ancient city of Olympos, enshrouded in dense vegetation, have received little excavation and, as a result, are wonderfully atmospheric. Being next to a river and shaded by tall firs, flowering oleander bushes, and a mountain gorge, they are also delightfully cool in summer, the perfect time to explore.
Olympos was once a top-voting member of the 2nd-century-BC Lycian League, but most of the buildings viewable today date from Roman times. Roman-era construction started in earnest after officers—including the young Julius Caesar—crushed a two-year-long occupation of the city by pirates in about 70 BC. Many tombs are scattered around the ancient city, which is reached by two parallel paths that continue down to the beach. In the center of the northern half of the site is the large cathedral complex, once the main temple, which includes a much-photographed 18-foot-high gate, dedicated to Marcus Aurelius in AD 171 and mistakenly referred to by signs as a temple.
Note how some walls around the site have clearly been rebuilt in later centuries with narrow arrow slits in the windows as if the city suddenly had to fortify itself. A second side path leads along a water channel to some interesting tombs and a large building, probably a grand mansion. At the beach exit is a poetic inscription on a sarcophagus in memory of an ancient ship's captain, along with a carving of his beached boat—not that different from today's gulets. From here you can also climb to a small acropolis and some medieval fortifications where ancients would keep a lookout for ships and pirates.
The southern side of the ancient city is best reached by crossing the riverbed (dry in summer) by the land-side ticket office and heading east toward the beach along a well-beaten path that starts with a remarkable row of tombs. Farther along are shipping quays, warehouses, a gorgeously overgrown theater, a bathhouse, and a church whose two great rows of granite columns have collapsed inward toward each other and now lie half-buried in what feels like the floor of a tropical jungle. Excavations by the river on what was probably the agora or marketplace began in 2011. Farther south along the beach are the walls of a medieval castle and church variously occupied and improved by crusaders and also used as an outpost of Italian city states.