Try to imagine, if you can, the mind rollercoaster of the couple from Sierra Nevada that found a can of coins on their property. First they're walking the dog and notice the top of a rusty canister poking out from the soil. Okay, they think, let's just get that out of the way. Then they realize that the can is full of old gold discs. Fine, they think. Just someone's penny collection from last decade.
Nope - they're $20 gold coins from the 1890s. Cool, they think, not a bad little find. There won't be more where that came from. Wrong again - there were a further eight cans of the coins in the same area, eventually totaling 1,427 coins, or $27,980 at face value. Which is pretty good for a walk in the field, right? Yeah, except that's just face value. They're actually now worth over $10 million.