Other things I've found:
A cave full of ancient rock paintings, some newer ones added by people who found the cave.
Several bunkers with assorted war trash, often the location of them is known but nobody can be bothered excavating them, considers them graves or are scared of UXO.
Found a bunch of drug caches, not interesting, I leave them alone.
Found a bunch of pegan shrines built by kids, hippies or actual pegans. Can't tell.
Found a ghost tree. Where a hollow tree dies and another grows out from the inside of it.
Found a bunch of money, usually just one coin or note. No idea why there's so much money in the woods.
A lot of junk that was dumped, but now qualifies as antique junk. Old fridges, toy cars, matress springs, industrial waste like slag and glass trimmings.
Found a lair someone built in a redundant branch of the storm water system. They'd tried to break the pipe and tunnel out a room or somthing but didn't get very far, I guess they had no way to reinforce anything but there was no cave in.
Found a mosaic someone made in a storm water section. The reason there is so many pipes is that 30 years ago anyone could pipe storm water into the river legally or illegally, the factories that did this covered up the end on their side and the river buried the opening, but if you know where the pipe was you can get into it by digging where the river used to be or smashing down into it. Bad air, most are blocked by roots.
Uh... I've found a lot of things.
