The ancient Tlos Castle area in Fethiye is one of the largest and oldest human settlements in ancient Lycia, located about 55 km east of Fethiye, and is believed to date back more than 4,000 years. Tlos was one of the six major cities of Lycia, and is believed to have been the most powerful and the capital of the Lycian civilization.
The city of Tlos brought together the Lycian, Roman, Byzantine and Ottoman Turkish populations and is considered one of the oldest cities until our present time. Tlos Castle is located on a wide plateau and includes many buildings and tombs carved into the rock of the Lycian peoples and contains a huge building on a rocky plateau, so that the castle today has become one of the most famous archaeological sites in Turkey.