Big Ben is the nickname for the Great Bell of the striking clock at the north end of the Palace of Westminster, although the name is frequently extended to also refer to the clock and the clock tower. The official name of the tower in which Big Ben is located was originally the Clock Tower, but it was renamed Elizabeth Tower in 2012, to mark the Diamond Jubilee of Elizabeth II, Queen of the United Kingdom.

The tower was designed by Augustus Pugin in a neo-Gothic style. When completed in 1859, its clock was the largest and most accurate four-faced striking and chiming clock in the world. The tower stands 316 feet (96 m) tall, and the climb from ground level to the belfry is 334 steps.

Big Ben is the largest of the tower's five bells and weighs 13.5 long tons (13.7 tonnes; 15.1 short tons).[1] It was the largest bell in the United Kingdom for 23 years. 

- Wikipedia