This is a video from my recent visit at Pietroasele, in Buzau county, southeast Romania, famous for a large Gothic treasure trove find, which it is now the main exhibit of the National Museum of History in Bucharest. The place also hosts a castrum/ fort, of no lesser historical importance, which was part of the advance warning outposts of the Roman Empire in the early 4th c CE, watching the corridor between the Great Bend of the Carpathian mountains and the Danube bend at Galati, a geographical feature linking the frontiers of the empire with the highways of migratory peoples roaming in the Pontic Steppe, the north Caucasus and Central Asia. Through this corridor fearsome peoples like the Goths, the Huns, the Avars or the Bulgarians will emerge like a whilwind and strike the empire at its heart, hastening its downfall.
I made a sketch map bellow, to illustrate the frontier geopolitics of the Roman Empire in the early 4th CE when Constantine the Great reigned, and the role played by Pietroasele outpost fort. Its purpose was to signal the advance of marauding hordes of migratory peoples approaching the empire, in many aspects similar with the radar early warning systems of nowadays, warning of approaching airplane fleets or missiles, and to provide a first frontline defence. It must have been manned by some of the best Roman soldiers of that era.