Ratiaria  Ratiaria (or: Raetiaria, Retiaria, Reciaria, Razaria; ; ;) was a city founded by the Moesians, a Daco-Thracian tribe, in the 4th century BC, along the river Danube. In Roman times it was named "Colonia Ulpia Traiana Ratiaria". It is located 2 km west of the present village of Archar in Vidin Province, northwestern Bulgaria. The closest modern cities are Vidin (27 km. to the north west) and Lom (28 km. to the east). An archaeological museum for the site has recently been established in Dimovo. Ratiaria was conquered by the Dacians of Burebista and later by the Romans. The city had a gold mine in the vicinity, which was exploited by the Thracians. The earliest involvement of the Romans occurred in 75 BC when Gaius Scribonius Curio, prefect of Macedonia, entered this territory to ward off the Scordisci, the Dardani and the Daci. In 29 BC, Marcus Licinius Crassus chased the Triballi here to a fortress. It was not until the principate of Augustus that the Romans conquered the region, which was organised into a province named Moesia. In 33/34 AD Tiberius built the road linking the Danube forts including Viminacium and Ratiaria. The city was certainly less important than the nearby Sirmium, Viminacium and Naissus, but its associated fortress located along the "Danubian Limes" made it a key legionary station. Legio IV Flavia Felix was based here at least until the conquest of Dacia (101-106 AD), together with the fleet of the "Classis Moesica" under Vespasian. After the conquest of Dacia, the "castrum" was abandoned and the settlement became a "colonia" within Moesia Superior named "Colonia Ulpia Traiana Ratiaria" (107 AD) after its founder the Emperor Trajan. In the 2nd and 3rd centuries Ratiaria became prosperous as a trade centre and customs port. A number of Roman patricians (aristocrats) lived in Ratiaria, while the nearby Bononia (today's Vidin) was home to a small military unit. With the definitive abandonment of Dacia Traiana by Aurelian in 271, the old "castra" in the region were reopened.