While in the Army, I had the opportunity to visit a side-lined boxcar that was filled with all the latest USGS maps. Later while in school, I worked in a map library and cataloged thousands of USGS maps that had piled up in a backlog. It was a little depressing to replace maps I had already cataloged with its newer edition. Interestingly, the university somehow acquired a set of topographic maps from Nazi Germany and every sheet was stamped with a spread-wing eagle clutching a wreathed swastika.
I went to a university that had a map room in the science library. Everything from official maps to old gas station maps.
Hours of entertainment.
By August of 1944, the Germans' investment in topo maps of the UK were not returning much of a dividend. My relative, however, got a dandy map out of it all to help him navigate what was left of the Thousand Year Reich's road network.