Like Lissos, Syia was a capacious and safe harbour of Elyros. Strabo calls the town Syba. The name derives probably from the word “sys, i.e. hog. Therefore, Syia is the “hog-city”. There might have been forests of oaks and hollies, which is the basic food of pigs.
Syia flourished in the Roman and the 1st Byzantine period. There are Roman ruins and three large Palaiochristian Basilicas. Syia had set up monetary union with Yrtakina, Elyros, Lissos, and Tarra. The city also participated in the Koinon the Oreians. It seems that the Saracens destroyed the city.
Robert Pashley detected ruins of the Roman water supply and thermae in the north by west of Elyros. In Syia, there are also relics of ancient buildings, walls, hollowed tombs, and the foundations of Roman houses. Pashley also observed inscribed crosses on marbles.