I slept late until about 10:00 and then had coffee at Morrison's. I went to Buckingham Palace to look around and just missed the changing of the guard at 11:00.
Then I walked through Trafalgar Square to Fleet Street and all the way down to St. Paul's Cathedral. There was a long line to get in so I will have to go back some other day.
Later I walked along the river back to Waterloo Station and then took the tube back to the hotel.