Location: London Date completed: 1859 Designers: Augustus Pugin Function: Clock Tower

Big Ben is probably one of the most instantly identifiable land marks in Britain and possibly the world. It is a sight familiar to millions of Londoners and tourists, a well loved symbol of British democracy. And yet what people know as "Big Ben" is not Big Ben at all. "Big Ben" is actually just the nickname of the Great Bell of the clock in the Elizabeth Tower. The Elizabeth Tower was renamed (it had previously been known simply as the Clock Tower) in 2012 to celebrate the Diamond Jubilee of Queen Elizabeth II.

In 1834 the Palace of Westminster was badly damaged by fire and in 1844 the architect Sir Charles Barry was charged with its rebuilding. He commissioned the great Augustus Pugin to design much of the interior of the new Palace, as well as the Clock Tower. Before he died in 1852 Pugin designed the Tower in his trademark Gothic Revival style, blending with Barry's designs for the rest of the new Parliament building. This is the tower that we know and love today.

Big Ben is 315 ft (96 m) high. The lower 200 ft (61 m) is constructed of brick faced with Yorkshire Anston stone and Cornish granite, while the upper part is a framework of cast iron, supplied by Regents Canal Ironworks. Iron roofing plates were supplied by a Birmingham foundry. The foundation stone for Big Ben was laid on 28th September 1843. The Tower sits on a concrete raft, 50 ft (15.2 m) square, set in foundations 10 ft (3 m) deep. Construction was completed in 1859, five years behind schedule, which probably explains why there was no opening ceremony.

The faces of the famous clock were also designed by Pugin. The clock movement sits in a frame 23 ft (7 m) in diameter. It was designed by a lawyer, Edmund Beckett Denison and George Airy, the Astronomer Royal, using a new double three-legged gravity escapement. "Big Ben" is the nickname of the Great Bell, 7 ft 6 in (2.29 m) tall and 9 ft (2.74 m) in Diameter, weighing 13.5 tons (1375 kg), that famously strikes the hour.