A speakeasy once occupied the building that now houses this museum, and the many mysteries surrounding the end of that enterprise—and the possible end of the underworld kingpin who ran the joint—make visiting here surprisingly dramatic and fun. I don’t want to give away the story, but I can tell you that to teach you about it, your guide will take you into the working theater and century-old pub below the museum, and then into the cellar, where you’ll don a hardhat to clamber through the operation’s former HQ (coincidentally, the foundation of a 17th-century fur trapper’s cottage is down there too). In addition, you’ll learn about the history of U.S. gangsters in general, with the help of such artifacts as the actual bullets that killed Bonnie and Clyde, an ice pick that Henry Hill himself donated, and more. Two warnings: To really get the full experience, you must take the 90-minute guided tour (included in the admission cost). Just seeing the permanent exhibitions, and not seeing the other parts of the building, won’t be nearly as compelling. And this is not an attraction for children under 12. Too many gruesome tales are told.