Take a trip to Paw Paw, WV (actually this cache is just over the river in Maryland but who'se counting?) This cache has everything. A 2 mile round trip hike with, almost half of that in the dark, a nice bit of C & O Canal history and if you like, it has a larger loop trail over the tunnel. Also, bike friendly if you want to go that route but you have to walk the bikes through the tunnel. We had a blast with this one. If you go, make sure to bring a flashlight so you can count the NGS benchmarks inside the tunnel. (We have pics of every one!) There are also benchmarks at either end of the tunnel in daylight if you don't bring a light.