The Elizabeth Tower is the clock tower of the Palace of Westminster in London, England. It contains the Great Clock, a striking clock with five bells. The tower is nicknamed "Big Ben", a name which was originally applied only to the largest bell of the clock. The tower was officially called the Clock Tower until 2012, when it was renamed to mark the Diamond Jubilee of Elizabeth II. The tower was designed by Augustus Pugin in a Perpendicular Gothic Revival style and was completed in 1859.