Perperikon was the name of the ancient Thracian city, located in the Eastern Rhodopes, 15 km northeast of the present-day city of Kardzhali in Bulgaria. Situated on a 470 m high rocky hill, it is thought to have been a sacred place. Perperikon is the largest megalith (large stone which has been used to construct a structure) ensemble in the Balkans.

The famous sanctuary and oracular and holy place dedicated to Sabazios (god of the Thracians) of the Bessi (Thracian tribes) was situated there.

Human activity in the area dates back 6000 years. The first evidence of civilization on the hill date from the Bronze Age, while the ceramics found on the place date from the Early Iron Age. There is also an impressive round altar, almost 2 m in diameter, cut out of the rocks.

At the time of the Roman Empire, a giant multi-story palace was erected according to archeological evidence, and an imposing with its size fortress was built around the hill, with walls as thick as 2.8 m. Temples and quarters of residential buildings were also constructed in the fortress.

The megalith complex had been laid in ruins and re-erected many times in history.

To visit you need to reach the village of Gorna Krepost  ("Upper Fortress") which is located at the foot of the hill. There is a large parking lot to leave your car and the journey to the top takes about 20 minutes. The sight is open every day  and currently (as of May 2010) it’s free of charge. There are experienced guides, some of which speak English, German or Russian, that could be hired for reasonable fee to accompany you on the tour to the holly place.  Allow at least 2 hours per visit.