Do this one as a fairly chill overnighter, or as an all day ride. It’s got some good Loudoun County gravel, including an absolute banger of a descent to the Potomac where you can see the Appalachian ridgeline through the trees as you fly down the hill. I’d recommend the Indian Flats campsite on the C&O because it’s a little farther away from the train tracks than Calico Rocks. For a night without train noise, head on to Marble Quarry (another 5ish miles down the trail) and backtrack in the morning. Plenty of spots to stock up on water and snacks, and pizza place in Point of Rock for a dinner or lunch stop.

(thanks Pedro for the photos!)