On one of the peaks of mountain Ypsario, on a longitude of 800m, lies the most ancient village of the island, Kastro. It took its name from the remnants of a castle that once stood there. It flourished in the years that piracy infested the Aegean Sea and was abandoned later when the locals found work at the iron mines of the Speidel company.At the villages’ square you can find the church of St.Athanasios. For many years the village was abandoned and it was until recently that local owners renovated their manors. In January,at the celebration of St.Athanasios, Kastro becomes vibrant and lively,as many Thassians join the feast with songs and food! Do not forget to visit the area called Apostoloi, where you can see the small waterfalls, and fresh up with a quick dive if you want! It is an amazing route from Kastro which lasts about 40 minutes on foot, through the deep green forest.