The settlement of Kastro, situated at a distance of 3 kilometers eastern to Apollonia, owes its name to the castle established there during the period of Frankish domination of the island. The castle had been constructed at the place of the ancient “asty” of the Classical period, a settlement that went back to the Geometric and Mycenaean times. The medieval settlement is fortified and, as it happens to other islands (Folegandros or Antiparos) the external walls of the houses form the defensive wall of the settlement, which has been built in an area naturally fortified and inaccessible. The history of the site is visible everywhere: you will observe several architectural parts of ancient buildings enwalled in the Venetian two or three-storey constructions which still preserve the blazons and inscriptions everywhere. Today, the settlement counts some 100 permanent residents, in their majority occupied in tourism.
Only a few accommodation facilities are available in Kastro, but as it happens with almost all the villages of Sifnos, the settlement has a lot of interesting sightseeing. First of all, you will find here low profile traditional taverns and pastry shops; at Seralia, the coastal settlement below Kastro, you will also find lovely fish taverns at the sea front.
Within the settlement it is worth seeing the small Archaeological Museum, where there are displayed sculptures of the Archaic, Classic and Hellenistic periods. There is also a collection of pottery and coins from various periods. The Museum is housed in an old mansion, restored in the 1980s’. The settlement itself, still retaining a medieval atmosphere, is an interesting part of the sightseeing. The entrances to the settlement, known as “Loggia”, are narrow and arched, so that they could provide the maximum protection to the residents. While strolling about, it is possible that you will find yourself walking …on the roofs of the old one-storey houses, which today serve as storehouses.
Within the medieval settlement you may visit numerous old churches as the Cathedral and the church of Panaghia Eleoussa (Virgin Mary of Charity), built in the 17th century, which has a nice wood carved icon screen and a small, but very interesting collection of religious and ritual objects. There are also the churches of Theoskepasti, also of the 17th century, where you may see nice old icons, the church of Aghios Nicolaos (St. Nicolas) of the 16th century, the church of Koimissi, dedicated to the Assumption of Virgin Mary, this too of the 16th century and the churches of Aghia Aekaterini (St. Catherine), Aghios Ioannis (St.John) Aghios Stefanos and several others. On the top of a high rock you will see the small church of Epta Martyres (“the seven martyrs”); once there you will enjoy a nice view of the sea. Below Kastro it is situated the coastal settlement of Seralia or Gialos (“beach” in Greek), which used to be the port of the island during the Medieval period. Finally, at a short distance northern to the settlement you may see the church of Panaghia Poulati, built in the 19th century.
Swimming is possible at the nearby beaches of Seralia, below the settlement and at Poulati, northern to Kastro.
In case of emergence you should address to the corresponding services of Apollonia, some 3 kilometers western to Kastro.
Access to Kastro from the port of Kamares or from Apollonia is possible by public buses running regularly, by taxi and by private means (car or motorbikes). The fans of walking will certainly enjoy walking from Apollonia to Kastro and back.