Wow... Some really interesting stuff on this thread.
The strangest thing I ever found was when I was like 10 or so -- I lived on 2.5 acres of land in rural NH, and was walking in the woods behind my house and stumbled across a large, freshly-dug hole. It was about 4-5 feet deep, almost the same in length and about 3 feet wide. It was kind of spooky.
Years later, in college, I was thinking about this experience and wondered if I had stumbled across some sort of grave. So, on my first summer break home, I went back into the woods to see if I could find it, and I did. Of course, the hole was no longer freshly-dug, but its outline and the pile of dirt next to it were unmistakeably still there. I still thought it was kind of spooky.
[Edit]:
raggedjimmi's list reminded me of one more strange thing I found. I was really young (8-9) and while at the park with my parents I found two film canisters filled with plastic bags filled with some sort of dried green plant. I couldn't understand why someone would do this, so I asked my mom why someone would fill film canisters with lawn clippings. She gave the canisters to my dad, who opened them, gave them a sniff, and promptly threw them down a storm drain. In high school, I put two and two together and realized I had found some dope. If only I still had the canisters then...
