I've found about a dozen elk sheds (rare in Ontario) some deer and moose ones too, old pop cans, jugs up on trees the normal stuff like that.
Interesting stuff:
Found a 300 sav way far north one time, in a case, not registered, in the middle of a stand of pines, didn't make any sense.
Chain connected to a wallet in the middle of a duck swamp I regularly visit. It must have been a few decades old seeing as the inch thick wad of bills had turned to mud, never pulled on the other end of the chain.
Crosscut saw about 20 miles from any river or civilization that would have existed when it was sharp.
The highlight for me was one day I was walking through the hardwoods at my camp and passed by an area with just bare ground, and there was a pile of stuff that didn't look natural, straight edges and stuff. I had noticed it a few times before and just assumed someone's snowmobile had brokend down there and they left some parts. So I took a closer look. Limestone arrowheads and a couple other implements. Really neat suff.
One day when I was driving down the camp road there were a bunch of police cars at my neighbours. He was standing outside so I asked him what was up. He was walking through his property along a cedar swamp where he never really goes since it's as thick as the amazon, and noticed a pretty heavily used trail going in to it, he thought it was a game trail and would follow it for a bit. About 40yds into the cedars in a small opening there was a bed with handcuffs on the posts, some bibles, mannequins and some photos of young boys (not there). That creeped me out for a long time.