In the “Northern” area of the Columbus Zoo there is this brilliant idea. It’s basically a place where kids can try panning for gold. The parents are convinced to buy one of three types of bags that contain dirt and “gemstones” and the kids wash the dirt out to get the stones. It’s a good fundraiser for the zoo, it’s fun for the kids, and it’s somewhat* historical.
* Were this available when I was a kid, I suspect I would have had complaints about the accuracy of the types of gemstones found as compared to the geology of the Klondike region it was purporting to be … but then, I always have had a hard time with the concept of “fun”.