On the position of Kydonia, which continued to preserve its strategic importance on the hill of Kasteli, a Byzantine fortress was later built, which in many parts intervenes in the ancient wall and has been constructed with the remains of ancient Kydonia.

In 1252, the city and the prefecture are divided in 90 feuds assigned to the Venetian settlers, who in turn had the obligation to rebuild the city of Chania. The Venetian settlers then ordered the construction of the wall of Kasteli and re-organized the urban plan of the city within the walls. Within the walls, a new modern city is built with beautiful public and private buildings. The public buildings were built lengthwise on the central road (corso - today the street Kanevaro) that crosses Kasteli from the east.  

In Kasteli, the noble houses of the famous Venetian families were concentrated, built according to the doctrines of the time, an especially of the 16^th century Venetian mannerism. There was also the majestic Cathedral Temple of the Venetians, dedicated to Virgin Mary (Panagia), which was later destroyed in the 1941 bombings.

Later, the notorious families of the Turkish-Cretans also established in this district, leaving their mark in the area. In Kasteli, there were two gates to the east and the west, as well as a third narrow one on the south, with a staircase.