Frontiers of the Roman Empire – Dacia

Rome's only province lying wholly north of the Danube needed a formidable frontier, and the Dacian Limes — operational from 106 to 271 CE — became the longest and most complex land border any Roman province possessed in Europe. Its 277 component parts stretch across Romania's varied terrain: legionary fortresses, auxiliary forts, watchtowers, ramparts and camps that once guarded prized gold and salt resources. UNESCO inscribed the ensemble as World Heritage in 2024.