Sucidava is a Dacian and Daco-Roman historical site, situated in Corabia, Romania, on the north bank of the Danube. The first Christian Basilica established in Romania can be found there and the foot of a Roman bridge over the Danube built by Constantine the Great to link Sucidava with Oescus, in order to start the reconquest of Dacia. There is also a secret underground fountain which flows under the walls of the town to a water spring situated outside.
From an archaeological point of view, the coins found at Sucidava show an uninterrupted series from Aurelian to Theodosius II. The archaeological evidence show that in AD 443 or 447 the city was sacked by the Huns, and was restored under Justin I 518-527 or Justinian I 527-565. Around 600, it seems that the Roman garrison abandoned the city.
Wikipedia https://en.wikipedia.org/wiki/Sucidava_(castra)
Address Romania
Coordinates 47°14'32.907" N 23°20'6.831" E