It is known as the Great Bell in the Palace of Westminster's Elizabeth Tower.
For millions of tourists Big Ben is probably the most famous landmark in Britain's capital.
Thousands of selfies and videos are taken in front of it every week by visitors who have traveled from as far away as Japan, China, Russia, the US and Australia.
The bell has sounded on the hour for the last 157 years and even the Luftwaffe failed to silence it in the Second World War.
The clock has witnessed numerous moments of history, including tragedies like the terrorist attack on Westminster Bridge in March this year.