The official office of British leaders since 1735, when King George II presented No 10 to 'First Lord of the Treasury' Robert Walpole, this has also been the prime minister’s London residence since the late 19th century. For such a famous address, No 10 is a small-looking Georgian building on a plain-looking street, hardly warranting comparison with the White House, for example. Yet it is actually three houses joined into one and boasts roughly 100 rooms plus a 2000-sq-metre garden.
The street was cordoned off with a large gate during Prime Minister Margaret Thatcher’s time, so you won’t see much. After an IRA mortar attack in 1991, the stout wooden door was replaced with a blast-proof steel version (which cannot be opened from the outside).
Unsurprisingly, you'll find that access to Downing St is restricted unless you're a head of state, but a few lucky souls who get drawn in the ballot can take a peek inside during Open House London and Open Garden Squares Weekend (www.opensquares.org).