Cool! Visiting Roman ruins in W. Germany was a favorite weekend drive to do when I was stationed there. That was one of the best things about having military topographical maps because they were well-marked on them.
There's quite a lot, too, and more found each year. For that matter, about ten years ago, a "rescue" dig in Copenhagen Denmark in a suspected old site turned up a Roman cemetery. Roman settlement, rule, trade, and influence was spread quite a bit farther east and north than has been the drumbeat for generations. There was no "Battle That Stopped Rome" -- when the Romans quit, they did so because of diminishing returns (IOW, there was nothing worth the cost of conquest, or, there were much richer pickings elsewhere all of a sudden).
All I remember seeing there of Roman times is the city wall of Regensburg (Castra Regina).