Arlington National Cemetery

The most important military cemetery in the United States, 639 acres of rolling hills across the Potomac from the Lincoln Memorial, with over 400,000 graves in uniform white rows. It was created in 1864 on the confiscated estate of Robert E. Lee, whose mansion, Arlington House, still crowns the hill with the best view over Washington. The two essential stops are the grave of John F. Kennedy with its eternal flame, and the Tomb of the Unknown Soldier, guarded 24 hours a day by the 3rd Infantry Regiment; the changing of the guard every hour (every half hour in summer) is precise and silent and draws a crowd. Around 25 to 30 funerals still take place each weekday.

Practical: Free, open daily from 8 am. Enter via the Welcome Center on Memorial Avenue, where there is a paid parking garage. The Kennedy grave and Tomb are a 20 to 30 minute uphill walk apart; a paid tram tour loops both. Allow two hours. Photography is permitted but the atmosphere is expected to be respectful. Ten minutes from the Pentagon by car.