Biertan gained its importance as a marketplace in competition with Mediaş and Moşna during the Middle Ages and was the seat of the bishop of the Evangelic Church from 1572 to 1867 . Therefore three mighty ring walls, two outer baileys and several defence towers protected the ensemble. The towerless three-nave hall church, almost completely preserved was built in 1500 on the foundations of a previous Romanesque building. The chancel had two defence levels, but the wooden one was demolished in 1803. The interior, covered by lierne vaults with ribbing shelters great treasures such as the stone pulpit from 1523, decorated with relief scenes or the late Gothic winged altar with 28 panel paintings and a delicate truss frame. The late Gothic sacristy door is a testimony of great craftsmanship. Richly decorated with inlay work, the door has a lock that was presented at the World Fair in Paris in 1889, a complicated system that centrally locks at 13 points simultaneously in order to safely keep the church treasure in the sacristy.
Romania's region of Transylvania has always been a very diverse place, consisting of Romanians, Hungarians, Germanic "Saxons", and others. One of the more notable features of Transylvania's landscape is that of the fortified churches. These unique churches were built during the late middle ages by the German minority group who were under constant threat from invaders. Since it was difficult for the armies of the Holy Roman Empire to ensure the protection of these villages, they were forced to build their own fortifications around the village's largest building, its church. There were once around 300 of these fortified churches, but today only around 7 of them are listed as UNESCO World Heritage Sites.
In place of the 14th century initial construction, a new church was built in the 15th century. Around 1500, during the fortification phase, the ensemble received its present appearance. The chancel was rebuilt as a tower featuring three brick defence levels and 1,5 m thick walls. The forth level projects over the lower part and is supported by the arches between the buttresses. It has a battlement platform built in the timber frame technique. A defence level was constructed above the main nave and the northern and southern entrances were provided with defence systems. The bell tower is impressive through its numerous and manifold defence systems. The church was surrounded by a curtain wall with battlement walk on brick arches, two bastions and a tower, as well as a gate tower provided with a portcullis. Inside the church a pew from 1528 was built during the transition phase between Gothic and Renaissance. The paintings of the altar were executed 1779 by Stephan Folbarth from Sighişoara.
The Câlnic castle was built around 1270 and equipped with a residential tower, defence wall and a water ditch featuring a drawbridge. After the castle was taken over by the Saxon community, it was expanded through the construction of a second defence wall and a southern tower. For a better defence against sieges, granaries and several rooms were attached to the fortification wall, however they did not last to the present day. The fortress was provided with a small single-nave church featuring a semicircular apse towards the end of the 15th century. During the construction of the second defence wall, the water ditch was covered up and the drawbridge replaced with a gatehouse featuring a portcullis. Today, an association of the University of Cluj administrates the facility.
The late Gothic aisle-less church was built between 1493 and 1525 replacing a Romanesque basilica. It was provided with a defence level sustained by high buttresses and extended over the nave and the chancel, which is only a little less narrow than the nave. The lierne vault of the nave was reconstructed in 1878. The interior furnishing is mainly Baroque, except the Gothic pew in the chancel, which is richly decorated with carvings. On the exterior walls, fragments of writings were preserved. From the initial defence wall, only the northern tower is still preserved. In 1677 it was provided with a distinctive spire, similar to the clock tower of Sighişoara.
The fortified church in Viscri still stands as a striking example of Transylvanian defensive architecture. On the foundations of the former Romanesque basilica, built by the first Székely settlers a new chancel was erected after dismantling the apse. In 1500 the church was fortified. Therefore the hall was prolonged and connected with the western, until then freestanding, dungeon, which most probably belonged to an early extinct noble family. The tower was heightened with one level with room for bells and parapet walk and another defensive level with loopholes for arches was built in the roof. The defence level of the chancel was demolished in 1743. The 7 m high ring wall was built in early 16th century and during the 17th century was strengthened by fortified houses, defensive towers and parapet walk. In the more peaceful times following 1743 grains storage rooms for the inhabitants replaced the parapet walk. The interior of the church still preserves the paneled ceiling from 1743 and the sober furnishing.
The church in Curciu has remained almost unchanged since its construction in the beginning of the 15th century. The remarkable value of the three-aisle basilica with polygonal chancel lies in its outstanding stone masonry. In the chancel the well preserved mullioned windows with tracery can be admired as well as the typical Gothic windows in the tower. The sculptures ornamenting the portals, tower, windows, buttresses, as well as the capitals, keystones, sedilia and the door of the sacristy date back to around 1427. At the beginning of the 19th century the side aisles were heightened, thus obtaining a cross section of a hall church. At the same time both the main nave and the side aisles were covered with a flat, stuccoed ceiling. The tower’s defence level was demolished and replaced in 1913 by the present, with zinc sheet covered spire. Today the ring wall with the gate tower initially used as entrance, as well as a Gothic chapel integrated in this wall still stands as part of the fortified ensemble.
The entrance of today’s church that was probably built in the 15th century from the remains of an older church, is located higher than it was initially. The floor of the nave was also raised by 2m, due to the repeated floods caused by a water stream which flows close to the fortification and which has brought over 3m of alluvial deposit over time, both inside the fortification and around it. The defence story comprises a first level built with stone, above which a second wooden level was raised and endowed with a parapet walk on buttresses and wooden consoles. The circular palisade that defended the church for 200 years was replaced in the 16th century by a fortified wall with defence towers. Inside the church there is a fountain from which villagers and tourists can obtain clean drinking water.