Southeast of Xanthi and over the coastline there is Avdira, an important archaeological site of Thrace and the homeland of famous ancient Greek philosophers like Democritus, who was one of the founders of ancient atomist theory. Other known philosophers born in Avdira were Lefkipos, Anaxarchos and the sophist Protagoras. The city was gifted with two natural harbors and a rich hinterland near the river Nestos.It was founded by mid 7th century by people who came to settle from Klazomenes, a city on the coast of Asia Minor. A century later it was inhabited by new settlers originating from Teo, a city located in Ionia. Avdira flourished during the classical period (5th century BC) and was preserved up until the Byzantine period wherein it was known as Polistylo, a name given to the city due to the numerous ancient columns surviving in the area. Excavations unearthed many buildings and other evidence of the city’s ancient past from the Classical, Hellenistic and Roman periods, like parts of the city’s walls, the Sanctuary of Demeter, sections of naval facilities and several dwellings, such as the “house with the dolphins” where mosaics with representations of dolphins were discovered.