The black door of 10 Downing Street is an iconic building in British and world politics.
Behind the door has been the official home to British Prime Ministers since 1735 and where decisions that have shaped Britain have been made.
Number 10 has 3 functions.
It is the official residence of the British Prime Minister: it is their office, and it is also the place where the Prime Minister entertains guests from Her Majesty The Queen to Presidents of the United States and other world leaders.
The Prime Minister hosts countless receptions and events for a whole range of British and overseas guests.
The building is much larger than it appears from its frontage.
The hall with the chequered floor immediately behind the front door lets on to a warren of rooms and staircases.
The house in Downing Street was joined to a more spacious and elegant building behind it in the late 18th century.
Number 10 has also spread itself out to the left of the front door, and has taken over much of 12 Downing Street, which is accessed by a corridor that runs through 11 Downing Street – the official residence of the Chancellor of the Exchequer.