The 4,000 sq m Venetian Castle of Astypalea was built in the 13th century by the Querini family and is perhaps the most important attraction of the island. Originally consisting of 400 houses built through the walls with the local dark stone, the Castle was the only settlement on the island until the 19th century. Basic characteristics of the castle are the coat of arms and the houses of the Venetian family of nobles Querini, built on the East side of the Castle, as well as the churches of Agios Georgios and Panagia of the Castle.
The Baby Cemetery
The findings of the infant cemetery of Astypalea date from the geometric period to the Hellenistic period were discovered in 1995. These are more than 2700 vessels of various species with extruded infants and toddlers which make the cemetery unique in the world.
The Archaeological Museum of Astypalea
The Archaeological Museum of Astypalea is located in Pera Gialos and started operating in 1998. The exhibits of the Museum vary and consist of jewelry, coins, vases, tombstones and altars, bronze and stone tools dating from the Prehistoric period to the Middle Ages.
The Castle of Agios Ioannis
The Castle of Agios Ioannis is worth a visit, although unfortunately only ruins remain. Built on a rock opposite the monastery of Agios Ioannis, probably due to its location it was a Byzantine fortress against pirates.
Other sights of Astypalea are Panagia Portaitissa and the Ecclesiastical Museum ,the baths of Talaras, the monument of the French Admiral Bisson located in Maltezana, the early Christian of Kareklis and Agia Varvara, as well as the natural caves, the windmills and the numerous chapels.