The most common "wrong" name for Big Ben is using it to describe the entire clock tower. "Big Ben" is technically only the nickname of the Great Bell—the 13.7-tonne behemoth that strikes the hours—and not the tower itself. For most of its history, the structure was simply called the Clock Tower. In 2012, to honor the Diamond Jubilee of Queen Elizabeth II, it was officially renamed the Elizabeth Tower. Another frequently used but incorrect name is "St. Stephen's Tower," which is actually a different, smaller tower located on the southwestern side of the Palace of Westminster. Even though most people around the world will immediately know what you mean when you say "I'm going to see Big Ben," a local Londoner or a history enthusiast will gently remind you that you are looking at the Elizabeth Tower, and you are only hearing Big Ben. This distinction is a classic piece of London trivia that differentiates tourists from true London experts.