The excavations at the Kastelli quarter proved that present-day Chania was built on the site of ancient Kydonia which was a flourishing city during the Roman period. This is why many graves, a rich collection of pottery from different periods, frescoes from the late Minoan period, a magnificent mosaic from the late Hellenistic period were all discovered here.
Still today you can see the remains of ancient Byzantine walls as you walk along Chalidon Street while heading towards Karaoli Dimitriou Street. The construction of the walls initially took place during the 1st Byzantine period after which it is believed that the Saracens destroyed the city in 828 A.D. During the second Byzantine period that followed which lasted until 1204 A.D, the city wall was fortified further using materials from the ancient buildings of the area.
After the Fourth Crusade and the failure of the Byzantium in the Hellenic area, Chania came under Venetian rule. The Venetians strengthened the wall, even more, giving Chania the form that it has today.
The new stones that formed the wall were built in coursed ashlar work and in many spots followed the form of the natural rock. It consisted of segments that were interrupted by orthogonal or polygonal battlements whereas the whole contour was oval with an irregular shape, shallow foundations and standard thickness throughout the height.
These walls were built between 1336 and 1356 but were not strong enough so about 200 years later in 1536, the famous Italian civil engineer. Michele Sanmichele came to Chania to design the more recent walls. Under his guidance, additions to the old walls were made and the construction was eventually completed in 1568.
In 1645, after a two months siege, the Turks overtook and occupied the town and as earlier rulers had done, added their own elements to the wall. In the years that followed, the walls partly fell on their own owing to their old age but mainly because the inhabitants themselves demolished them to build new structures. As a result, what remains today is only a few but precious ruins of this once magnificent structure.