I'm 30 miles W NW of the center of DC out in the far Maryland burbs. They reach out 100 miles now. I was reading the thread, but it is not about things that I can speak to. Now if you are interested in things from later wars and redneck road houses, then I might know a few. The new Air and Space annex would be worth a look, it's at Dulles IAP, near Manassas. The Enola Gay just went on display.
I don’t camp with the hikers, so I can’t help you there. They tend to scare the game off
Be forewarned, anything down here that attracts tourists is BMWya.