On the northwest side of the port of the city of Chania, the Venetians built the Revellino del Porto, a fortification project to protect the port.
Its construction began around the middle of the 16th century. and was completed a few years before the fall of the city and its occupation by the Turks in 1645.
In case of siege, a thick chain from Firkas to the base of the lighthouse at the other end of the entrance, closed the port.
The Turks used the castle as a barracks and so it got its name that is preserved to this day, as "Firkas" in Turkish means barracks.
The positions of the cannons on the north side of the fortress, which looks at the entrance of the port, are still visible on the outer side of the wall.
In each of the 6 vaulted openings along the walls there was a cannon (the openings are now built), while above them, the rectangular openings allowed the shooters to observe the trajectory of the shot in order to make the necessary corrections for the next shot.
To sink the enemy ships, it had to hit them near the surface of the sea. That is why the positions of the cannons are at the lowest height of the walls, at ground level.
- The carved entrance on the first floor of the two-storey building, where is preserved the lion-emblem of the Serene Republic of Venice.
- In the middle of the yard, the vaulted floor with the vertical holes, is the roof of the large underground tank that collected rainwater.
- In the background are the vaulted areas where the cannons were located. These vaulted areas were used as prisons from the years of Ottoman rule until the years of the civil war.
In the corner turret of Firkas, was the place where the flag for the union of Crete with Greece was raised on December 1, 1913, in the presence of the King Konstantinos, the Admiral Koundouriotis, the Prime Minister of Chania Eleftherios Venizelos and many people.
Since then, the blue-white flag of Greece flutters at the turret of the fortress, and the anniversary of the union of Crete with Greece is celebrated every year on December 1, by organizing a similar ceremony at the Firkas fort.
The entrance of the fortress is located on the south side and is identified with the entrance of the current Naval Museum of Crete which is built on the walls and inside the fortress.