Mindenum

Minden is a town in North Rhine-Westphalia, Germany. It is the capital of the district of Minden-Lübbecke. It has a station on the railway connecting Hannover and the Ruhr (the Hannover–Minden and Hamm–Minden lines).

Mindenum in Give Me Back My Legions!
Mindenum was a large Roman camp in the middle of the Germanic province. It was large enough to contain three Legions (the XVII, XVIII, and XIX). Publius Quinctilius Varus made it his summer headquarters. The legionnaires would demolish its fortifications each fall when they returned to Vetera and then reconstruct them when they returned in the spring.

Literary Note
In the Historical Notes at the back of Give Me Back My Legions!, Harry Turtledove indicates that archaeological findings indicate that the Romans had a large camp at modern Minden but their name for it was not known. He therefore made up a classical sounding name based on its modern one.