Pyrgos Kallistis or simply Pyrgos is a picturesque village on the Aegean island of Santorini, Greece, in the Cyclades archipelago with a population of approx. 732 according to the 2001 census.
Pyrgos is part of the Municipality of Thira and is situated approximately 7km 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.