The Series Historic Buildings in Transylvania, launched in 1993, presents the most precious examples of Transylvanian built heritage connected to the Hungarian culture, with the purpose of drawing the general public's attention on values, heritage and our responsibilities towards these. The publications of this series are recommended especially to those who at present own or use such values, but also to those who are interested in history, architecture and the Transylvanian art.

Number 39 of the Series Historic Buildings in Transylvania presents the fortifications of Cluj. The first fortification of the settlement (the hill fort of the county) was built on the territory of the Benedictine monastery from Cluj-Mănăştur, but during the 11^th-12^th centuries the County seat separated itself from the ecclesiastical institution and was installed in the Old Castle, placed in the north-western corner of the Antique fortification of Napoca. The castle and the village, ravaged during the Tatar invasions, were rebuilt and repopulated with Saxons by Duke Steven V. The settlement, which during the Middle Ages got ever stronger, in 1405 becoming a free royal town, from that moment on started to build of the “New Castle”, which took almost a century. In the 19^th century, the largest part of the walls and towers were torn down, preserving only the Old Castle's south-eastern tower and the towers of the firemen, tailors, masons, joiners, boot makers, as well as some fragments of the southern curtain wall.