Cheyenne Mountain, near Colorado Springs, is the home of an important NORAD facility. I’ve always thought it would be cool to take a tour. I’m not sure if it’s still the case, but there used to be Canadian personnel stationed there as well. At any rate, there also used to be a similar facility in North Bay, Ontario. I believe it’s been closed for several years. Then, of course, there’s the Diefenbunker — I’ve got that on my list of must-see Ontario tourist attractions.