The Byzantine Wall surrounds the hill of Kasteli, where the first inhabiting of the city is located.
It was built in 12th century and its outline is irregular with longitudinal axle from the East to the West, where its two central gates were located.
The Wall consists of rectilinear parts, interrupted by small oblong or polygonal towers, and is founded over the ruins of an older fortification of the Hellenistic period.
The visitor can see it during the tour in the roads of the old city of Chania.
Source: chaniatourism.com