Stare into the jaws of a Tyrannosaurus Rex, stroll through a primeval swamp, whip up an 11-foot tornado and take a microscopic look at all the cool things a body can do at one of the Midwest’s top museums. Expect a busy, full day of exploring, starting with the fifth-floor exhibit on the Mighty Mississippi, with sweeping views of the real river and the chance to step into a towboat pilothouse. (Insider’s tip: You can also earn free Junior Ranger badges at the Mississippi River National Park Service office in the museum’s lobby.) Among the museum’s most popular artifacts: an Egyptian mummy, a traditional Hmong home, a 32-foot wave tank and a staircase that plays like a xylophone. For an extra fee, immerse yourself in deserts, oceans and outer space, with a nine-story domed IMAX theater, or check out traveling national exhibits that have featured King Tut, the Titanic and pirates. Summer visitors play mini-golf on the riverfront and wander a prairie maze in the Big Back Yard.