Took me 3 years to figure out the shell midden in my backyard wasn't just a pile of old trash
I kept digging up oyster shells behind my shed in Beaufort, SC and tossing them back until a retired archaeologist down the street mentioned that a 4,000 year old Native American midden could be sitting right under my tomato plants, so now I'm wondering if I've been gardening on top of somebody's dinner for a decade.
The archaeologist thing is cool but the shells might not be a midden at all. People in the Lowcountry dumped oyster shells behind their houses for decades, some for fill, some just to get rid of them after shucking. If the pile has no other stuff mixed in like pottery pieces, broken bones, or dark stained dirt, it's probably just a old trash pile from somebody's backyard oyster roast. Real middens have layers and all kinds of junk in them, not just shells stacked in one spot.