Well at least that's what is on the coin. When I first dug it up all I could make out was the $100 marking and a goldish color; couldn't tell if it was a coin or a token. Turns out it is a 1991 Mexican 100 peso coin. Its an aluminum-brass alloy slightly larger than a US quarter and twice as thick. Since it was minted in 1991 it is no longer legal tender in Mexico since the peso was revalued since then. You guessed it, its worth about $0.10 American. Still, its always fun finding something different. You should have seen my wife's eyes light up when I told her I found a $100 dollar coin.