Washington, D.C.

A 3 km axis of lawns from the Capitol to the Potomac, lined with Smithsonian museums and memorials, ending at the Doric temple of the Lincoln Memorial, where Martin Luther King gave his 1963 speech.

💡 Visit the memorials after dark: they are lit, open at all times and almost empty after 9 pm. In late March and early April, the cherry blossom around the Tidal Basin draws huge crowds, so come at dawn. Price: free.

G. Edward Johnson / CC BY 4.0 (Wikimedia Commons)

A 169-metre marble obelisk completed in 1884, whose change in stone colour marks the Civil War pause, with a lift to a 152-metre observation deck overlooking L'Enfant's city plan.

💡 Timed tickets are free at the Washington Monument Lodge kiosk, on 15th Street, from 8.45 am on the day, while places last; online on Recreation.gov, up to 30 days ahead, they cost a $1, about €1, booking fee. Open from 9 am to 5 pm, closed one day a month for maintenance. Price: free, excluding the booking fee.

U.S. Air Force Tech. Sgt. Andy Dunaway / Public domain (Wikimedia Commons)

Opened in 2016 under a bronze lattice crown by David Adjaye, with history galleries rising from the slave trade three levels underground to civil rights and present-day America.

💡 Allow at least three hours and start with the underground galleries, the densest. Entry requires, for everyone including babies, a free timed pass, bookable online 30 days ahead; more are released online every morning at around 8.15 am for the same day. Open from 10 am to 5.30 pm, from 12 pm on Mondays, last entry at 4 pm. The Sweet Home Café serves regional African American cooking. Price: free.

Frank Schulenburg / CC BY-SA 4.0 (Wikimedia Commons)

Two free buildings linked by a tunnel, the neoclassical West Building with the only Leonardo da Vinci painting in the Americas and several Vermeers, and I. M. Pei's triangular East Building.

💡 Start with the West Building in the morning, then go through the tunnel with its carpet of lights to the East Building and its terrace with a view of the Capitol. Open daily from 10 am to 5 pm, except 25 December and 1 January, with no ticket or reservation. Bags are checked at the entrance. Price: free.

AgnosticPreachersKid / CC BY-SA 3.0 (Wikimedia Commons)

The Smithsonian's museum of flight on the Mall, with the 1903 Wright Flyer, Amelia Earhart's red Lockheed Vega, John Glenn's Friendship 7 and the Apollo 11 command module Columbia.

💡 Entry requires a free timed pass, to be booked online for all visitors, babies included; once inside, you can stay as long as you like. Open from 10 am to 5.30 pm every day except 25 December, with a single entrance on the Jefferson Drive side. Some galleries remain closed while the work is completed. Price: free.

DiscoA340 / CC BY-SA 4.0 (Wikimedia Commons)

The seat of Congress under its cast-iron dome, visited on a free guided tour of the crypt, the rotunda with the Apotheosis of Washington fresco and the National Statuary Hall.

💡 Book the tour online on the visitor centre website; without a reservation, arrive before 2.30 pm to be placed on an available departure. The security check is strict, so check the list of prohibited items, food and drink included. The galleries of the two chambers are not part of the tour. Price: free.

Beethoven / CC BY-SA 4.0 (Wikimedia Commons)

The Thomas Jefferson Building of 1897, the most richly decorated building in the city, with the marble Great Hall, the Main Reading Room dome, Jefferson's own library and a Gutenberg Bible.

💡 Entry requires a free timed ticket, bookable online up to 30 days ahead; same-day tickets are released online every morning at 9 am. Open Tuesday to Saturday, until 8 pm on Thursdays, closed on Sundays and Mondays. Ask in the Great Hall for a free ticket for the five-minute walk through the reading room. Price: free.

APK / CC BY 4.0 (Wikimedia Commons)

A port founded in 1751, older than the capital itself, with cobbled streets, Federal brick houses, the shops of M Street, the C&O Canal towpath and the Gothic towers of Georgetown University.

💡 Rent a kayak on the banks of the Potomac, under the Key Bridge, to see the Lincoln Memorial from the water, or follow the canal towpath on foot. The metro does not serve Georgetown: take a bus, a bike share bike or walk 20 minutes from Foggy Bottom. Price: free.

Wknight94 talk / CC BY-SA 3.0 (Wikimedia Commons)