St. George's Castle, Ottoman fortress in Preveza, Greece

St. George's Castle is a fortress in Preveza with high polygonal bastions and walls set at angles to deflect artillery fire. The structure follows early 19th-century military design with thick stone walls and strategic defensive positions around its perimeter.

Ali Pasha of Ioannina retook Preveza in late November 1806 and ordered this fort built as his first major work in the town. French engineers Frédéric François Guillaume de Vaudoncourt and Captain Ponceton drew the plans; work ran from February to autumn 1807, using several hundred unpaid Greek labourers and masons. It guarded the channel from the Ionian Sea into the Gulf of Arta.

The fortress represents Ottoman military engineering, incorporating French architectural expertise and Greek construction knowledge through local stonemasons and workers.

The fortress sits at the western edge of Preveza near Kyani Akti beach and can be viewed from outside along the waterfront. Public interior access is not currently available, but the exterior walls and fortification layout are visible from the surrounding area.

The castle's Ottoman name Hizir kalesi links to Khidr, the "Green One", a Muslim figure venerated on the same day Christians honour Saint George. A church of Saint George stood on the site before the fort was built, which explains the name it received after 1912.