Every year, Demographia, a consultancy based in Missouri's fashionable St Louis area, publishes its World Urban Atlas, measuring the populations of the world's urban areas and ranking them by size. The Atlas is a great opportunity to prove, once and for all, that Lyon has more residents than Leicester.
But how well do you know your city sizes? There's only one way to find out.
In each of the questions below, we're looking the city that has the largest population. And by "city", we mean "urban area", rather than "official administrative district".
So we don't accidentally give you any clues, and because we're an internet-based publication, each question comes with its own kitten pic.