What is "ratiaria"

Ratiaria (or: Raetiaria, Retiaria, Reciaria, Razaria; ; ; later named Colonia Ulpia Traiana Ratiaria) was a city founded by Moesi, a Daco- Thracian tribe, in 4th century BC, along the river Danube. The former Archdiocese was revived as Latin Catholic Metropolitan titular archbishopric. The city had a gold mine in the vicinity, which was exploited by the Thracians.

It is located 2 km west of present village 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).