Marian Koshland Science Museum of the National Academy of Sciences

Though modestly sized and featuring only five exhibitions at a time, this museum, named after immunologist and molecular biologist Marian Koshland, proves something of an eye-opener. State-of-the-art, interactive displays teach visitors by doing, not just showing. At the time of writing, exhibitions covered global warming with Earth Lab: Degrees of Change; images of earth at night with Lights at Night; the ageing process with Life Lab, along with the self-explanatory Safe Drinking Water. In addition, Wonders of Science examines recent research aiming to unravel some of the greatest mysteries of the universe.