The castle of Skyros towers above what was once the fortified main town of Chora. While it is not accessible to visitors as it is being renovated due to damage by earthquakes, it is still interesting to learn about this structure and fort around it. A walk up to the nearby courtyard is highly recommended.
The outer wall of the fort still boasts remains of four semicircular towers (Agios Nikolaos Agia Parskevi facing east, Palaiopyrgos facing north and Pergos facing west). There are important walls that descend to the eastern coastline between Agia Paraskevi and Agios Nikolaos towers. More recent walls were built over the ancient fortifications of the acropolis, although some stones from the older structures still remain. There are also three water cisterns inside the upper part of the castle that were probably built during Venetian times.