In1687 the Treaty of Blaj was signed, a document through which the Habsburg Empire required a number of 12 cities in Transylvania to provide shelter to its troops during the winter. The moment represented the beginning of the Austrian incursion in Transylvania. As for Cluj, the medieval fortifications of the city were considered outdated, with inadequate accommodation possibilities for the empire's soldiers. As a result, it was decided to build a new fortress, on Cetățuia Hill, a strategic location due to the panoramic view over the old city center. The construction of the fortress began in 1715 and was completed after approximately 20 years. The citadel was used as a prison for 200 years and many people were imprisoned and killed here. Amongst them was the Saxon pastor, Stephan Ludwig Roth, executed on March 11th, 1849. Roth was an important figure of the Romanian Revolution from 1848. He was a humanist thinker, historian and teacher who supported the idea that the Romanian language should become the official language in Transylvania. One of the main access roads to the Fortress was the Wiener Tor, built in 1734, which was rehabilitated following investments of about one million euros. The renovation of the old gates was completed in 2019, and the building is treasured by its inclusion in the tourist and commercial circuit of Cluj-Napoca.
The Wiener Tor is part of the entire bastion fortress and housed rooms for soldiers on the first floor. At the same time, it provided access for vehicles on a road that surrounds the hill to the north. Inside, in front of the main gate, were raised two buildings of more considerable size: the building of the fortification command and a barracks. Three other smaller buildings were located in the area of the Appeal gate: at its north, the powder shop, and in front of the entrance, the bakery with a specific V-shaped plan and food store
The building retains its initial form, suffering at the end of the 19th century and around the 1970s extensive interventions, after which the Baroque stone frames and the carpentry of the building were almost completely changed. The façades of the building have a simple aspect, without any vertical articulation, and without the marked base, only the main profiled cornice appears on all the façades of the edifice. Another important feature of the façades is the use of limestone frames on the windows with rectangular closure. Most of these frames were placed during a major repair of the building, probably the one around 1970, when the commemorative plaque dedicated to the memory of Stephan Ludwig Roth was also installed. Only one single frame from the Baroque era, the one from the northern window of the western façade, was preserved. The windows do not have a profiled notice, the profiles of the uprights continuing on the lower part of the opening, a process often used in the Baroque architecture. The main façade of the building is the southern one, inside the fortification. The main axis is accentuated by the presence of the opening in the form of a bow, unmarked by framing or other decorations. Due to the presence of the ground wave, the northern façade of the building has only one level, its entrances being opened directly from the floor of the building.
Although this gate was the most important access within the fortress, the carved limestone frame is distinguished through its simplicity, a characteristic of military architecture. The central area of the gate was deepened to provide a retreat to the mobile bridge. The building floor was accessible through the two open doors in the side rooms of the respective level. The Wiener Thor is on the list of historical monuments and it represents an attraction of the city already.