What are the most worthwhile things to do in Washington DC on a first visit?

The Mall is a single two-mile argument about the country, and it is open around the clock. The memorials at its western end — Lincoln, Jefferson across the Tidal Basin, Vietnam, Korea, World War II, Martin Luther King Jr. — are free, need no ticket and stay open 24 hours a day under National Park Service care. The one interior that requires planning is the Washington Monument, the world's tallest freestanding stone structure: admission is free, but every visitor aged two and up needs a timed ticket. Advance tickets are released on recreation.gov at 10 a.m. exactly 30 days ahead for a non-refundable $1 service charge per ticket, and they routinely sell out the day they drop; a second batch is released the day before each tour date, and a limited number of free same-day tickets are handed out at the Washington Monument Lodge on 15th Street from 8:45 a.m., first come, first served.

The museums flanking the Mall belong to the Smithsonian Institution: twenty museums and galleries plus the National Zoo, seventeen of them in Washington and eleven on the Mall itself, every one free to enter. The exception list is short and worth memorising — free timed-entry passes are required at the National Museum of African American History and Culture, the National Air and Space Museum on the Mall, and the National Zoo — while the Natural History, American History and Hirshhorn museums simply take walk-ins. All Smithsonian museums close only on December 25.

The two non-Smithsonian anchors reward the same trick. The Library of Congress's Thomas Jefferson Building admits visitors free on timed-entry tickets reservable up to 30 days ahead, with same-day tickets released online at 9 a.m., and the National Archives, where the Declaration of Independence and the Constitution are displayed, is free with an optional $1 timed entry that skips the line.

Inside the Lincoln Memorial at dawn, Daniel Chester French's seated Lincoln fills the chamber at the top of the steps, the marble still cool, and through the columns the Reflecting Pool runs straight as a ruler to the Washington Monument in first light.

The Washington Monument closes for a full day in the first week of almost every month for routine maintenance, as well as on July 4 and Christmas Day — a trip built around a single date can lose its slot to a published closure that nobody mentions at booking time.

• Morning — Start at the Capitol end and walk west while the light is low, taking the museums on the south side of the Mall.
• Midday — Go up the Washington Monument on your reserved slot, then cross to the museums on the north side as the crowds peak outdoors.
• Evening — Return to the memorials after dark, when the Lincoln and Jefferson memorials are lit and the tour buses have gone.

The 30-day ticket release is the trip's real deadline: miss the 10 a.m. drop for the Monument and the fallback is a dawn queue at the Lodge for same-day tickets that the Park Service warns typically run out. Museum opening days also vary across the Smithsonian — some buildings close on certain weekdays — so a Tuesday plan and a Saturday plan are not interchangeable.

Build the eating around the U Street corridor, fifteen minutes from the Mall — the food question in this group explains the half-smoke, mumbo sauce and the Ethiopian table.