Downing Street in London is where the Prime Minister and Chancellor of the Exchequer live and work. It's a cul-de-sac off Whitehall, with Number 10 as the PM's official residence and Number 11 for the Chancellor. The street was built in the 1680s by Sir George Downing, and over time, it became home to government offices and officials. It's like the hub of British politics, where important decisions are made and leaders meet.