The Houses of Parliament and Elizabeth Tower, commonly called Big Ben, are among London's most iconic landmarks. Technically, Big Ben is the name given to the massive bell inside the clock tower, which weighs more than 13 tons (13,760 kg). The clock tower looks spectacular at night when the four clock faces are illuminated.
You can take a tour of the Houses of Parliament. The Elizabeth Tower is not open to the general public although UK residents can arrange a visit by writing to their MP.