On a low hill of mount Panachaicos, 800m from the seaside, stands the castle of Patras. It was built over the ruins of the ancient acropolis in the second half of the 6th century A.D. The walls, built by Justinian with material from early Christian buildings, cover a surface of 23 hectares.

The castle was besieged by the Slavs, Saracens, Bulgarians and Normans but it was never conquered. In A.D. 805 the inhabitants of the city were besieged in the castle by the Slavs and Saracens and their victory was considered a miracle of the city’s patron saint Andrew.

In 1205, the Frank crusaders occupied the castle and extended and reinforced its structure. Constantine Palaiologos also carried out some repairs and additions.

The Turks occupied the castle in 1458 and handed it to French General Maison, in 1828. During the German occupation (1941-1944) it was used by the German forces for the defense of city.