If you ever wanted to visit every interesting historical site in the U.S., this map will guide you on a tour to each one using the mathematically shortest route possible.
The map, created by University of Waterloo professor William Cook and his team of researchers, uses Google Maps to figure out the shortest route to see every single site listed on the U.S. National Register of Historic Places. It's one heck of a road trip, though, as the entire tour covers over 350,201km -- or somewhere between eight and nine laps around the equator. Fortunately, the massive map is separated into four different regions of the U.S., making it useful for any traveller looking to maximise their tour of specific regions of the country. You can find the map at the link below.