Synaxis is an important seaside archaeological site 10 km east of Maronia on the road leading to Petrota and the Ancient Zone in the Prefecture of Evros. This site includes the foundations of the 4th-century BC sanctuary of Maronas, where a clay mask of Dionysus was discovered and is now exhibited at the Archaeological Museum of Komotini. There are also the ruins of a large guest-house complex that is believed to have accommodated pilgrims visiting Samothrace and the Island of the Great Gods, given that the Synaxis is the closest mainland point to Samothrace.

The site also features the ruins of an early Christian-Justinian three-naved basilica, a monastic complex dating back to the 9th century AD, a chamber tomb, and a chapel with a mosaic floor. It should be noted that the archaeological site is not suitable for group visits, however, in cooperation with the Ephorate of Rhodope a guided tour can be organized. Adjacent to the archaeological site is the homonymous Synaxis beach, which attracts visitors looking to enjoy the sea while being surrounded by the authentic ancient Greek landscape. The marine area has no organized beach suitable for swimming but also for recreational fishing.