Cisnădie was mentioned for the first time in a document from the year 1204 under the name "Rivetel". In the 12th century Saxon colonists settled here, and in 1323 the German name Heltau is mentioned. The town flourished, particularly the guilds of blacksmiths and wool weavers (weaving remained the traditional occupation of the town population until the 20th century, when large textile factories were built).
Cisnădie shared most of Transylvania's eventful history. The town suffered several raids, starting with the 1241 raid of the Mongols and continuing with Ottoman attacks. The plague did not spare the town, neither did the fire nor political agitations. In 1806 under Emperor Franz of Austria, Cisnădie/Heltau renewed its market rights, proving prosperity.
The two World Wars demanded their tribute, and in 1945 large parts of the German population has been deported to the Soviet Union.
In 1948 all factories were nationalized and run under the Communist regime. Along with its fall, most of the factories collapsed, but in the last years the economic situation has been ameliorating.
The most important architectural sight of Cisnădie is the fortified complex located in the town center. Originally built in the 12th century as a Romanesque basilica, the church was fortified during the 15th century, to protect the local population of Saxons against repeated Ottoman raids. The fortification process included the construction of fortified towers over the two side entrances and the choir, the building of a double structure of defence walls, a moat and several defensive towers along the walls. Simultaneously to the fortification work the church itself suffered a gothicization process. The altar inside the Lutheran church, which forms the center of this complex, is a wing altar/triptych from the 15th century, realized by the school of Veit Stoss Jr.
The complex is very well preserved and besides being a medieval architectural place of interest, it offers a variety of theme exhibitions:
- the "Cisnădie/Heltau throughout 12 centuries" Museum located over the old Ossarium
- the Museum of Medieval Defensive Structures located in the northern side tower
- the Museum of the History of the Communist Era
- some alternating Art Expositions.