Not far from our house is an old railroad bridge abutment. It's back in the woods a little ways, and you can still see a couple of ties on the roadbed. Downtown, you can see a couple of vacant lots that used to be rights of way. Most of this was pulled up in the late '70's. A little research, a little imagination, and you can still see signs here and there where the right of way was: a little raised, straight line in the middle of a corn field, a strange little cut on the side of a hill, a peculiar bend in a road. Google earth helps, because you can see some straight lines where there shouldn't be any.
So my winter project, IF I get ambitious enough, is to take the old bike out and try to trace some of the railroad tracks within 10 miles from home, and take a couple of pics. I get bored with pointless riding in circles; having some thing to go see, or some reason to ride really helps with motivation. Also, winter is better than summer for this since the undergrowth is less, and you can actually see some things much better.
I'd save the in-town stuff for those days when I can just grab a half hour or the temperature is well below freezing.
Ideally, the bike would pre-date the year the track was pulled up. That won't always be possible, as there is some around here that was pulled in eighteen fiftyfive.