Big Ben is not the name of a man. It's the name of a big clock in London. This clock has four faces. So, no matter where you stand, you can read the time on the face of Big Ben. Each face is the size of a bus. The hands are about four meters long. If you go to London, you may want to visit the Houses of Parliament(英國議會大廈). In that place you will find Big Ben sits at the top(頂端)of the clock tower in the Houses of Parliament. You will probably hear it and see it. The big clock makes such a loud noise. It goes every quarter of an hour. Big Ben has been the most famous symbol(象征)of London.