The changing of the guards at Buckingham Palace is crowded and difficult to see the whole event unless you get there early. However, it's one thing that your friends back home will ask if you attended when visiting London! The changing of the guards happens at 11:30 every day in the summer and about every other day the rest of the year. The band does not march if it is raining. The best views are from the Victoria Monument just outside the gates.
Although it looks like one of the guards in this photo is going the wrong way, he just had not yet turned around.