The Castle of Oria, located above the village of Salmeniko in Achaea, near Aigio on the slopes of Mount Panachaikon, is one of the most historically significant medieval fortresses in Greece. It is renowned as the last castle in the Morea (Peloponnese) to fall to the Ottoman Empire, after a heroic resistance that lasted for more than a year. In 1461, the fortress was defended by the Byzantine commander Konstantinos Palaiologos Graitzas, whose determined stand has become a symbol of the final resistance of the Byzantine Despotate of the Morea against Ottoman conquest.Today, the castle’s ruins stand as an important monument of Greece’s medieval heritage, offering panoramic views of the surrounding mountains and the Gulf of Corinth. Nearby lies the historic village of Salmeniko, home to one of the oldest surviving stone bridges in Greece, further enhancing the area’s historical and cultural significance. Together, the castle and the ancient bridge form a remarkable destination for visitors interested in Byzantine history, medieval architecture, and the natural beauty of Aigialeia.