Ratsiaria was a large and important city on the Danube. Its ruins are located in Kale, at 1 km northeast of the present village, Archar (about 27 km. southeast of Vidin). The town was founded during the Roman Empire, and the resolution of the Thracians conflict happened in this place in the late 4th century BC. During Roman time the roman patricians lived here (aristocrats) and near Bononia (today District) was based only a small military unit.
It is a turning point in the history of Ratsiaria during Vespasian (69- 79). There have been found many pieces of silver and gold, even from that time. During his reign, the city was fortified and the Danube fleet has been strengthened.
In the centuries second-third Ratsiaria became one of the most important cities in the eastern districts of Upper Misia and of the lands today in northern Bulgaria. Archaeological investigations have discovered architectural fragments, sculptures, tombstones and inscriptions, sarcophagi and other objects of great value.