Two Harbors, Minnesota
"Abrasives are a part of everyday life," declares one of the exhibits in this small museum. It's housed inside the little building where the 3M Company began in 1902, and where sandpaper, 3M's first product, was invented. The sandpaper part of the museum occupies two small rooms, with displays of natural raspy things (flint, emery), sandpaper samples, and examples of products that are sanded (shoes, tools, etc.). 3M executives visit, but they're interested in the company historical displays. You'll likely have the sandpaper rooms to yourself.