I expected to spend a couple of minutes browsing this, yet 25 minutes later I'm not even halfway through.

The best (so far) are the ones above the strings "on June 2nd, 1940" and "effort by Russian War Relief". I can't imagine the amount of research and sheer work (especially pre-internet) to create these.

I was a kid who played SimCity 2000, RISK, and had tons of books about geography. Having physical pieces of paper that I'd spend minutes or hours analyzing was so satisfying. Scrolling around Google Earth or doing GIS-based analysis is also satisfying, but I really got a kick out of looking at this post (putting aside the seriousness of WW2).