The world’s population keeps rising and is expected to peak at around 10.4 billion in 2100, according to the United Nations. More than half of people already live in cities, and that figure is expected to reach almost 70% by 2050.

Some cities have grown so large they are now classed as “mega-cities” with more than 10 million residents. Based on population data from the World Population Review, the biggest city on Earth has 37 million people, more than London (9.8 million), New York (7.9 million) and Paris (11.3 million) combined. 

Here are the 7 biggest mega-cities in the world: