Westminster and Royal London

This is postcard London at its best. Crammed with historic churches, grand state buildings, and major art collections, the area unites politics, high culture, and religion. (Oh, and the Queen lives here, too.) World-class monuments such as Buckingham Palace, the Houses of Parliament, Westminster Abbey, and the National Gallery sit alongside lesser-known but lovingly curated museums redolent of British history. If you have time to visit only one part of London, this is it.

Royal London's basic layout can be divided into three distinct areas—Buckingham Palace, Whitehall, and Trafalgar Square—grouped at the corners of triangular St. James's Park.

Trafalgar Square is the official center of London. To its north are two major museums, the National Gallery and the National Portrait Gallery. From Trafalgar Square two boulevards lead to the seats of very different ideas of governance: Whitehall leads to the Houses of Parliament, whereas The Mall, a wide, pink avenue beyond the stone curtain of Admiralty Arch, heads toward the Queen Victoria Memorial and Buckingham Palace, the sovereign's official residence. Halfway down Whitehall, the Queen's Life Guards sit motionlessly on horses in front of Horse Guards Parade, adjacent to the glorious Banqueting House.

No. 10 Downing Street, diagonally opposite, is home to both the residence and the office of the prime minister. One of the most celebrated occupants, Winston Churchill, is commemorated in the Cabinet War Rooms & Churchill Museum, his underground wartime headquarters off Whitehall. Just down the road is the Cenotaph, which acts as a focal point for the annual remembrance of those lost in war, and at the end of Whitehall you'll find Parliament Square and the neo-Gothic Houses of Parliament, where members of both Houses (Commons and Lords) hold debates and vote on pending legislation.

On Parliament Square's west side is Westminster Abbey, a site of daily worship since the 10th century. Poets, political leaders, and 17 monarchs are buried in the 13th-century Gothic building. In its shadow is the 16th-century St. Margaret's Church, Parliament's "parish church." Heading west along Birdcage Walk will bring you to Buckingham Palace. The building is open to the public only in summer, but you can see much of the royal art collection in the Queen's Gallery and spectacular ceremonial coaches in the Royal Mews, both open all year. Finally, farther south toward Pimlico, Tate Britain focuses on prominent British artists from 1500 to today.