Millions live there, millions more visit each year – but how many really know London?Find out:How New York’s famous Central Park came to be modelled on a seventeenth-century London squareWhen Primrose Hill almost gained a pyramid even larger than the Great Pyramid of CheopsWhy about 640 people came to be drowned in the Thames in a single nightWhat the royal family might do to escape London if the balloon ever goes up
