Built on a natural terrace west of the Rhine, Novaesium was, together with Nijmegen, the oldest military base in Germania Inferior, founded by Drusus before 16 BCE. He used this base, which is exceptionally large, to conquer the valley of the Lippe. When the conquests had been given up, Neuss remained in use as a Roman fortress, at least until the end of the first century CE.
The camp village survived the departure of the legionaries; the town was still in existence in the Merovingian age. The site of the ancient fortress is overbuilt by modern use, but many objects have been excavated.
I uploaded extra photos, which I took in the Clemens Sels-Museum. It’s all here.