After the Palace of Westminster was destroyed by a fire in 1834, the plans for the new building included a tower and a clock. It's construction started in 1858 and the clock first rang on 31 May 1859. This is the largest four-faced chiming clock in the world and it's one of the most recognizable symbols of London.

Even though everyone refers to the clock tower as Big Ben, initially this was just the nickname for the great bell of the clock. But today 'Big Ben' is most often used to refer to the clock, the tower and the bell collectively. Still, some consider this extension to be incorrectly used.

The four dials of the clock are 23 feet square, the minute hand is 14 feet long and the figures are 2 feet high. Big Ben is an excellent timekeeper, which has rarely stopped.

At night, all four faces of the clock are illuminated and when the parliament is in session a light shines above the clock face.