Big Ben is the most famous clock tower in the world, and it is one of the most frequented landmarks by visitors and tourists when they are in London. This tower has many names, including "Elizabeth Tower", "Big Ben Tower", and "Parliament Tower Tower". The name Big Ben is often used to describe the tower, clock, and bell, but the first name given to it was the Great Bell. Elizabeth Tower was completed in In 1859, the Great Clock began to move on May 31 of the same year.