If you have only one day in London, and you've never been there before, here is a tour full of famous and interesting sights.

Recommended guide book: London A to Z, a detailed street map of London available everywhere books and newspapers are sold.

Major sights: Buckingham Palace, St. James's Park, Horse Guards, Admiralty Arch, Trafalgar Square, National Gallery, National Portrait Gallery, Church of St. Martin-in-the-Fields, Whitehall, Downing Street, Houses of Parliament, Big Ben, Westminster Abbey.

The tour is circular - start anywhere on this route. The closest London Underground (Tube) stations are shown in brackets after the name of each major site on the tour.

1. Buckingham Palace (Victoria Station, Hyde Park Corner, Green Park, St. James's Park)

The Queen's official residence. Changing of the Guard ceremonies and inspection of the guards may be seen - check current schedules. The ceremony can be crowded during peak tourist season. For a one-day visit, see the Palace at your convenience and move on to the next destination rather than wait for the ceremony.

Buckingham Palace is open to the public (admission charge) during August and September only.

2. With Buckingham Palace behind you, walk away along The Mall. St. James's Park is on the right.

What to see here: Clarence House (Prince Charles' home) on the left. The Horse Guards change daily at 11:00 a.m. in Horse Guards Parade at the end of the park farthest from the Palace.

3. Pass through the Admiralty Arch.

4. Bear left and proceed toward Trafalgar Square (Charing Cross; many London buses stop at or near Trafalgar Square as well).

Nelson's Column, the four massive sculpted lions, and the pigeons (fewer now but still there), are all London icons.

National Gallery

Admission is free (donations are encouraged). Extensive art collection, unique shops, restaurants. A good place to take a break, indulge in some art and perhaps have a coffee or lunch.

National Portrait Gallery

Less frequently visited than the National Gallery, the National Portrait Gallery is just steps away and offers an illustrated history of the United Kingdom as told by the portraits of the many historic figures shown here.

St. Martin-in-the-Fields Church

Rich in history, open to the public. Underneath, the Cafe in the Crypt offers light dining at reasonable prices.

5. Exit Trafalgar Square to the south and proceed toward the River Thames on Whitehall.

The gate with the much-photographed guard on horseback is at the entrance to Downing Street. "Number 10" is the official residence of the Prime Minister of the United Kingdom.

Whitehall changes its name to Parliament Street as you pass the Cenotaph.

6. Continue along Parliament Street to Parliament Square. (Westminster, St. James's Park)

Big Ben is the clock on the British Houses of Parliament. Optional detour: Go about halfway across the Westminster Bridge to get a river's eye view of London and the Thames.

7. Leave the Houses of Parliament and follow the signage (and the crowds) away from the river toward Westminster Abbey. (Westminster, St. James's Park)

There is an admission charge to tour Westminster Abbey, but if time allows, the visit and the audio guide (additional charge) are worth it, if you enjoy history and architecture.

8. From Westminster Abbey, follow the signs for the Cabinet War Rooms, crossing Parliament Squrae and heading toward St. James's Park.

Cabinet War Rooms (admission charge) include exhibits about Winston Churchill and the Second World War.

9. Follow Birdcage Walk or walk through St. James's Park, back to Buckingham Palace.

The advertisement below is for the London A to Z. This is a street map of London, in a handy book form. I recommend the 5 inch by 7 inch format, with coil binding. The book is easy to buy in London, but if you want to plan ahead and leave the book at home, here's a link to Amazon. I would not think of spending any time in London without a map, and this is the all-purpose version. It is a map only - no commentary, not a guide book.