Pyrgos Kallistis or simply Pyrgos is a village on the Aegean island of Santorini, Greece, in the Cyclades archipelago with a population of 1,078 according to the 2021 census. Pyrgos is part of the Municipality of Thira and is situated approximately 7 km away from the island's capital Fira. It is built amphitheatrically on a hill that offers magnificent views of Santorini in almost all directions. On top of this hill remain the ruins of a Venetian castle (Kasteli) that was once the island's administrative center. Pyrgos is a typical example of medieval architecture with narrow, labyrinthine streets, fortified walls and hidden passages. Nowadays it is one of the villages of Santorini least spoiled by tourism.