Epano Kastro (Upper Castle) in Potamia, Naxos island: Close to the village of Ano Potamia, there is a hiking path leading to Epano Kastro, also known as the Castle of Tragea or Tsikalario Castle. This path is not easy but totally worth it when you reach up there. At an altitude of 420m, there is an old imposing castle with view to the valley of Tragea on the east and the village of Potamia on the west. The strategic location of this castle shows that it was a point of reference for central Naxos and allowed good observation over the entire region.
Epano Kastro was the residence of the Duke of Naxos in the Medieval Times. It was originally constructed by the Venetian Marco Sanudo, who eventually chose the Castle in Naxos Town as his residence. Few ruins of old buildings survive until today, like ruins of storehouses and watchtowers. The walls are largely destroyed by time and wars.
Close to castle walls are the two Byzantine churches of Panagia Kastriani and Saint George. At the bottom of the hill, there are also two ancient cemeteries from the Geometric period. Findings from these cemeteries are today hosted at the Archaeological Museum of Naxos.