Colonia Claudia Ara Agrippinensium

Colonia Claudia Ara Agrippinensium is the name of the Roman colony from which modern Cologne grew. In AD 50 the emperor Claudius raised the original Oppidum Ubiorum to the rank of a full colonia at the request of his wife Agrippina the Younger, who was born in the town, and gave it the elaborate title preserved in the abbreviation CCAA. The city served as capital of the province of Germania inferior, garrison for 8,000 men and key node on the Rhine route; it covered about 96 hectares within a city wall of 3.9 kilometres that is almost entirely traceable today. Traces are everywhere in Cologne: the Roman Tower on Zeughausstrasse, the Praetorium beneath the city hall, the Dionysos Mosaic at the Romano-Germanic Museum and the surviving north gate. The site became a UNESCO World Heritage Site in 2021 as part of the Lower Germanic Limes.