Big Ben is nickname for the Great Bell of the Great Clock of Westminster. This famous bell can be found at the top of the clock tower located at the north end of the Palace of Westminster. Originally known simply as the Clock Tower, it was renamed Elizabeth Tower in 2012 to mark the Diamond Jubilee of Queen Elizabeth II. 

The tower was completed in 1859 and standing at 316 feet, it is the third tallest clock tower in the United Kingdom. 

Since then, the famous clock has continued to give the time with such precision for more than 150 years.
Today, it is an icon that can be seen in movies, TV series, shows and documentaries set in London.