Located near the western entrance of the citadel, the impressive Orthodox Cathedral was built between 1921 and 1923 to celebrate Transylvania’s reunification with Romania. The first monarchs of unified Romania, King Ferdinand I and Queen Marie were crowned there on 15 October 1922.

Grandiose building, the Reunification Cathedral was built between 1921-1923, following the project drawn by the architect D.G. Stefanescu, leaded by the engineer T. Eremia. The Great Romanian monarchs were crowned here on the 15th of October 1922. The establishment is shaped as a Greek cross, with an open porch. One can get inside trough a right-angled narthex with three round headed vault units, a narrow have and a sanctuary. Constantin Petrescu painted the fresco in traditional iconography style.

Built in 13th century, the Roman Catholic Cathedral is considered to be an important monument of early Transylvanian medieval architecture. It harmoniously combines Gothic and Roman style elements. The establishment was meant to be a three Trinitarian three semicircular absides transept. Undoubtedly, the most important early Transylvanian Renaissance building is "Lazo" Chapel situated on the northern side of the Cathedral. The Chapel has a late gothic pointed arch. The keystone is decorated with blazons of some Transylvanian personalities. Inside the cathedral there is Iancu of Hunedoara`s sarcophagus next to those of his elder son Ladislau (situated in the lateral southern nave), of Queen Isabella and of son, Ioan Sigismund (situated in the opposite lateral nave).