The fame of Parliament, coupled with the splendour of the buildings, means that it comes top of the 'to do' list of most overseas visitors, and must be the UK's most photographed place.
Home of the oldest parliamentary democracy in the world, the Houses of Parliament have already outlasted dozens of prime ministers and thousands of debates.
King Canute is believed to have first established a palace on the spot, and, to this day, Westminster is still designated a royal palace - hence the term Palace of Westminster.
In 1834, a fire destroyed most of the buildings. However, it was something of a blessing in disguise, as the replacement - built between 1840 and 1852 - proved to be a magnificent palace.
Architect Charles Barry, who won a competition for the best design, and interior designer Augustus Welby Pugin created a palace more than fit for a king, in the Victorian Gothic revival style. It combines imposing, spacious chambers with intricate decoration, and awe-inspiring opulence with hosts of corridors and offices.