There are more than 1,000 rooms and more than two miles of corridors!
The clock tower is the most photographed part of the Houses of Parliament. It houses five bells. The biggest and most famous bell is called Big Ben.
The Houses of Parliament is also called the Palace of Westminster and was a royal palace. The last monarch to live here, Henry VIII, moved out in 1512. Parliament has met in the Palace of Westminster since around 1550.