London: the world’s most visited city. Home to the red double-decker bus, Big Ben, Tower Bridge, Changing the Guard and the black taxi.

That “most visited city” tag, which caused a recent flurry, is a little dubious. It is based on the International Passenger Survey, which is based on a sample of interviews with passengers coming and going from the UK. The Office for National Statistics candidly describes it as an “estimate”.

Still, London draws millions of tourists and has become a global capital while maintaining its traditional symbols – except for that boxy black taxi, which is now the whatever-colour-you-like whatever-shape-you-can-think-of taxi. No city competing for tourists would throw away something as distinctive – except for London, which has.