Not sure if this place is considered "hidden" anymore. I met as many tourists like myself as I did locals. I got good info on local sites from the patrons at the bar. Check out the "blue hole" and No Name Key, both only a few minutes drive away. I saw Key deer roaming No Name Key and a gator hanging out at the Blue Hole.
Try the No Name amber and a fish sandwich or pizza. There are thousands of one dollar bills hanging all over the place. The exterior was much nicer than I had expected and would not consider this place a "dive bar." The prices were in line with the other Florida Key bar/restaurants, expensive. Give it a go if you can find it. Follow the signs to No Name Key and look out on the left side of the road before you get to the No Name Key bridge.