Muzeul Principia (Castrul Roman Apulum)

The Principia Museum in Alba Iulia brings back to light the Roman fort of Apulum, one of the most important military centres of Roman Dacia. The Thirteenth Legion Gemina was garrisoned here, and the fort gave rise to a thriving urban settlement that would later become the nucleus of the city. The museum is organised around the principia, the central command building of the fort, where the military altar, the archive and the shrine of the standards were located.

Visitors can see the foundations and remains uncovered through archaeological research, together with reconstructions and explanatory materials that convey the daily life of the soldiers and the organisation of the imperial army. Set within the imposing Alba Carolina citadel, the museum completes a rich historical route that begins in the Roman era and reaches the 18th-century Vauban-style fortress. Practical note: the visit combines easily with a tour of the citadel and the other landmarks of Alba Iulia, and the underground spaces can be cool.