The Castle of Mytilene one of the largest and most important of the Eastern Mediterranean is located at the highest point of the northeastern edge of the peninsula of the city where the ancient acropolis was once built It occupies an area 300 m long and 150270 m wide that extends from the top of the hill to the northwestern slope reaching up to the northern port The Great Perivolos is the fortified acropolis of the castle of Mytilene and has many building phases starting from the Byzantine period with its final form in the years of the Genoese It includes a high tower and courtyard surrounded by high walls which are reinforced by strong towers. almost in its entirety the Great Perivolos of the Castle which is the most monumental and impressive surviving part of the Castle