Imagine rolling out your sleeping bag beneath a 50-foot whale, at the home of the Star-Spangled Banner, in the shadow of the space shuttle Discovery, or near the portraits of presidents and visionaries. That’s exactly what kids and their grown-up companions can do when they attend a Smithsonian Sleepover. The American History Museum, Natural History Museum, the Air and Space Museum’s Udvar-Hazy Center, and the National Portrait Gallery are all yours during a night of fun that features tours, games, crafts, and more. Which adventure will you choose?