On a related note, if you’re around Washington, DC in the US, then the National Cryptologic Museum[1] is well worth a visit. They have a ton of equipment on exhibit, including a variety of mechanical encryption machines as well as early supercomputers.
It doesn’t get that many visitors, because it’s within Fort Meade (home of the NSA), and most people probably don’t even realize it’s open to the public.
I second this: don't go down the wrong entrance, but definitely do visit. It's a fun time with knowledgeable employees that will take you on a tour. You can also see some of the machinery used to crack Japanese codes and some historical attempts at codes and code-breaking. It's a fascinating place.
It doesn’t get that many visitors, because it’s within Fort Meade (home of the NSA), and most people probably don’t even realize it’s open to the public.
[1] https://www.nsa.gov/museum/