About 10 years ago...I was working on a field survey team, doing topographical location work over in East Baltimore City, Maryland, on the grounds of Bayview Hospital {where I was born 67 years ago); when I happened to look down at the bottom of a 6 foot deep curb storm drain inlet grate, I spotted a rusted-out Saturday Night Special (revolver}.
I called hospital security, and they brought out a car unit to the location. I helped them retrieve it with a rope attached to a large magnet, that I kept onboard the survey truck that I worked out of.
Some years ago...somebody found a rusted-out Civil War rifle, that was still leaning against a tree; on the grounds of where the Civil War "Battle of South Mountain" (Maryland) took place.