Knidos was an ancient Greek city near present-day Datça, Turkey. The town of Datça is located on the Datça Peninsula, which juts out into the Aegean Sea. Knidos was an important cultural and political center by the 5th century BC and, due to its location on the sea and large harbor, it was a major trading hub as well. The city was a member of the Dorian Hexapolis, which was a federation of six cities of Dorian Greek origin. Over time the city became part of the Roman empire and survived into the Byzantine era.
Eventually the city was abandoned. Excavations began in the 1800s, and many ruins have been uncovered. Today you can see the ruins of temples, an altar, a sundial, a theater, a sanctuary, the agora, and churches, including the remains of a Byzantine church. The biggest find is the necropolis, which is almost four miles long. The theater could seat 5,000 people and was built with an impressive panoramic view of the sea. Although many statues and artifacts are now housed in the British Museum, there is still a lot to see here, and even just for the view, it's worth a visit.
The Knidos ruins are open daily from 8:30am to 7pm. Tickets cost 8 Turkish lira, or about US $3.60. The site can be reached by local transport or boat from nearby villages. The closest big city is Marmaris, which is about 45 miles away.