More than just a clock, Big Ben is one of the most prominent and photographed symbols of the United Kingdom and celebrated its 150th anniversary on May 31st, 2009. The tower is officially known as the Elizabeth Tower and holds the second largest four-faced chiming clock in the world (the first being at Minneapolis City Hall). The beauty of the tower must be enjoyed from the outside though as public entrance is not allowed. A few more fun facts: The name Big Ben actually refers to the clock’s hour bell, the largest of the clock’s five bells. The other four are used as quarter bells. The clock is also known for its reliability and has rarely failed. Even after the nearby House of Commons was destroyed by bombing during World War II, the clock kept on chiming. It’s rate is adjusted by simply adding small pennies on the shoulder of the pendulum.