Things to do at the Smithsonian museums

The Smithsonian is not one museum but roughly a dozen separate, free, walk-in museums strung along the National Mall, each keeping its own hours.

Two exceptions break the walk-up rule: the National Museum of African American History and Culture and the National Air and Space Museum both require a free timed-entry pass, released online about a month ahead or the same morning once reservations open, capped at nine passes per person.

Leave either building and you generally cannot re-enter without booking a new slot the same day. Veterans, active-duty military and first responders can usually skip the advance pass at NMAAHC and enter on ID alone. Budget at least half a day per museum, and a 15-20 minute walk between the Mall's far ends.