The National Mustard Museum One of the most unexpectedly fun stops I made while in Middleton, Wisconsin? The National Mustard Museum. And yes… it’s exactly what it sounds like. 😄 Inside you’ll find thousands of mustards from every U.S. state and countries all over the world, all displayed in this massive wall of jars. There’s also a mustard tasting bar where you can sample tons of different flavors — from classic yellow to sweet, spicy, and some seriously unique combinations