Free general admission (timed-entry passes required — book in advance at si.edu) makes this one of the best value stops on the National Mall. Open daily 10am to 5:30pm with extended hours in summer. Kids can touch a real Moon rock, walk through a NASA space shuttle, and explore flight simulators (simulator rides cost around $10 extra). The museum is fully stroller-accessible with elevators throughout. The nearest Metro stop is L’Enfant Plaza (served by four lines) making this easy to reach without a car, which is the preferred approach since Mall parking is limited and expensive.

Address: 600 Independence Ave SW, Washington, DC 20560

Google Maps: Click here for directions

Cost: Free