There isn't actually a subway connecting all the National Parks, but this map is still fun.
Well, it looks like the Sierra Club is starting to get a bit more social media-savvy. The group recently created this subway-style map of the U.S. National Parks for its Facebook page. It's not to scale, nor is there an actual mass transit system connecting all these parks (though wouldn't that be nice?), but it is fun. I'm embarrassed to admit I've only been to five of these.