It starts with Queen Elizabeth's birth and then goes around the corner where Prince Charles bought Princess Diana's engagement ring.
(Click through for video of the tour.)
Prince William gave his mother's ring to Middleton.
Also on the tour is the Mahiki nightclub where, after a brief break-up with Middleton, Prince William reportedly jumped on a table, shouted "I'm free!" and racked up a $17,000 bar tab in a week.
Thousands of tourists are expected to visit London for the royal wedding. Walking tours are expected to make a royal pile of money for the British economy.
The tour comes to an end at Westminster Abbey, where Prince William and Middleton will begin their new journey on April 29.