It is located in Filyos town of Çaycuma district. Filyos, BC III. It is a Miletus colony established for commercial purposes in the 16th century. The city is known as an important trade center where goods brought from the north of the Black Sea were unloaded in antiquity.

There are ruins such as a castle, an open air theater, an underground city, aqueducts, and an ancient harbor pier in the town, where the Roman, Byzantine and Genoese ruled in various periods. History BC. The "Tios - Tieion Ancient City" dating back to 1200 is still waiting to be unearthed with the ongoing archaeological excavation. Filyos Castle, thought to have been built by the Romans, was built on a promontory, which is a point overlooking the sea in the city. In order to give it a strong and imposing appearance, large stones were used in its construction.

The first settlement is on the castle hill in the north of the city. Today, there are walls belonging to the medieval castle and tower remains dating back to the Hellenistic-Roman periods. To the east of the castle hill, marble columns and pedestals, marble inscriptions, stone sarcophagi and brick tombs were unearthed.