The historic center of Berat is divided into three quarters. Gorica and Mangalem are the two historic quarters located along the river banks in the lower city; while the upper part within the fortification is the third quarter called Kala (Castle). Most of the urban architecture in these quarters dates from the 18th-19th century and emerged under the influence of the Late Ottoman Empire.
The Kala quarter, the citadel, occupies the top hill and it is situated within a fortification wall circuit. These fortifications date from pre-Roman times (4th century BC) and the later of middle Ages. The layout of this quarter is labyrinth-like and includes traditional dwellings, churches, ruins of mosques, and garrison strongholds, from the 13th up to the 20th century. This quarter has around 140 dwellings that have been listed as monuments of culture.
Without question, the churches in this quarter remain a particular feature of both the Byzantine and post-Byzantine periods. The castle includes 15 churches, the main ones of which will be described in this guidebook. The citadel also preserved the ruins of two mosques, which belonged to the Turkish garrison from 1417 until 1830, the year of their abandonment. Another engineering feat of the Byzantine period is the Great Water Cistern. This vaulted cistern is situated atop acropolis, within the garrison fortress.