World's Largest Cities Trivia

More people now live in cities than in the countryside worldwide, and a handful of metropolitan giants account for a staggering share of that total. This quiz explores the biggest urban centers on every inhabited continent.

Megacities, Defined

The term "megacity" generally refers to an urban area with a population over 10 million. There were only a couple of these a century ago; today there are dozens, and the vast majority are concentrated in Asia, a shift that tracks the region's rapid urbanization over the last several decades.

The Usual Suspects

A handful of metro areas consistently top global population rankings.

• Tokyo, Japan
• Delhi, India
• Shanghai, China
• Mexico City, Mexico
• Lagos, Nigeria

A Word About Rankings

Comparing "biggest" cities is trickier than it sounds, because sources disagree on whether to count the historic city center, the built-up urban area, or the entire metropolitan region. Chongqing is the classic cautionary tale: it shows up near the top of some lists purely because its administrative boundaries sprawl across an area roughly the size of Austria, not because it has a single, continuously built-up city to match.