The fortress on the northwest side of the port was constructed to protect the entrance of the port and maintains its Turkish name "Firká" (Firka=barracks). A chain from "Firka" to the lighthouse blocked the entrance to the port in case of intrusion. The fortress was the headquarters of the Army Commander of the city.
In the interior, the spaces were organized to barracks and ammunition storage areas. On a door case of the 1st floor there is the inscription "ALOYSIUS BRACADEUS PROVISOR CYDONIAE M.DCXX".The buildings of the west wing have two floors with domed chambers. In about the middle of the courtyard, there is a large water tank that gathered rain water from the roofs. From the years of the Turkish period until recent years, the "Firka" fortress was used as barrack, but also as a prison.On the corner watch tower the Greek flag of the Unification of Crete was raised on December 1st 1913. The king of Greece, Konstantinos and the Prime Minister Eleftherios Venizelos were present, as well as the Admiral Kountouriotis, the survivor leaders of the Cretan revolutions, and a large number of people.Nowadays, this anniversary is celebrated with an official ceremony and re-enactment of the event.