The name Big Ben is often used to describe the tower, the clock and the bell but the name was first given to the Great Bell.

The Elizabeth Tower was completed in 1859 and the Great Clock started on 31 May, with the Great Bell's strikes heard for the first time on 11 July and the quarter bells first chimed on 7 September.

The clock inside the tower was the world's largest when it was installed in the middle of the 19th century. 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 known for its reliability, it has rarely failed during its long life span. Even after the nearby House of Commons was destroyed by bombing during World War II, the clock kept on chiming. The clock's mechanism, designed by Edmund Beckett Denison, has a remarkable accuracy. The clock's rate is adjusted by simply adding small pennies on the shoulder of the pendulum.

The clock tower is not publicly accessible, but if you're looking for views over London the London Eye and the Shard are currently the best options.

Facts:
Dimensions: over 96 metres and 12 metres square
Steps to belfry: 334
Steps to lantern (the Ayrton Light): 393

Amount of stone used: 850 cubic metres
Amount of bricks used: 2600 cubic metres

Number of floors: 11