If you're like me, in addition to the big famous landmarks and parks, you also like to go find obscure historical stuff that most people maybe don't know or care about. If so, check out these arrows and beacons that the US Postal Service used for cross-country night airmail navigation in the late 1920s and early 1930s. You can still find a lot of these arrows out there. Here's a brief youtube summary of what the hell I'm even talking about https://www.youtube.com/watch?v=-DfzbnW2DTI . And here are a few websites that catalogue this stuff, if you're looking for something a little more obscure to go hunting for on your next trip out into the middle of nowhere.
This one is very comprehensive regarding location, with few other details: https://thesurveystation.com/airway-beacons-list-western-u-s/
This one is pretty comprehensive by state, a lot more driving-landmark-style directions vs just straight-up lat/longs, and some more pictures and descriptions: https://www.dreamsmithphotos.com/arrow/arrows.html
This is the most descriptive website, both regarding the location of the sites and how to find them, as well as the description of the sites with pictures and stuff. It has the fewest number of locations though, I believe they prioritize high-quality arrows only: https://sometimes-interesting.com/concrete-arrows-and-the-u-s-airmail-beacon-system/
submitted by /u/PiriperoSerra