The Royal Sightseeing Triangle leads to all of London's must-see attractions: Big Ben, the Houses of Parliament, Westminster Abbey, the Churchill War Rooms, Buckingham Palace, St. James's Palace, Trafalgar Square, the National Gallery, St. Martin-in-the-fields, the National Portrait Gallery and Horse Guards Parade. Follow my "Royal Sightseeing Triangle" to all these attractions in just one day. Plus, visit the bar where Bond's "shaken, not stirred" martini was created, grab a bite at the Cafe in the Crypt or a pint at the Sherlock Holmes pub and take a sunset spin on the London Eye. This is an easy to follow two-mile or three-kilometer route through the heart of the British capital that you can take at your own pace.