Big Ben is the nickname for the great bell of the clock at the north end of the Palace of Westminster in London, and often extended to refer to the clock and the clock tower. The tower is officially known as the Elizabeth Tower (prior to being renamed in 2012 it was known as simply "Clock Tower") to celebrate the Diamond Jubilee of Elizabeth II. The tower holds the largest four-faced chiming clock in the world and is the third-tallest free-standing clock tower. The tower was completed in 1858 and had its 150th anniversary on 31 May 2009, during which celebratory events took place. The tower has become one of the most prominent symbols of the United Kingdom and is often in the establishing shot of films set in London.
The clock and dials were designed by Augustus Pugin. The clock dials are set in an iron frame 23 feet (7.0 m) in diameter, supporting 312 pieces of opal glass, rather like a stained-glass window. Some of the glass pieces may be removed for inspection of the hands. The surround of the dials is gilded.
Clock Tower of Westminster Palace - is one of the most recognizable symbols of the UK, often used in souvenirs, advertising, movies.