The world's megacities, such as Lagos in Nigeria and Bengaluru in India, have populations of well over ten million people, but what does that look like in comparison to other, possibly more familiar areas? Visual journalist Matt Daniels has created this engaging digital essay addressing this topic for The Pudding, an online magazine that features visual essays and data visualizations. In this essay, Daniels uses maps showing three-dimensional representations of population density for large cities around the world to explore their patterns of development and population distribution. As visitors progress through the essay, they are presented with series of maps comparing cities like London and Paris, whose population distributions both show extensive suburbanization in their outskirts, to cities without such suburbanization like highly planned Singapore and geographically isolated Kinshasa. Daniels also discusses several areas in China, such as the Pearl River Delta, that are termed mega-regions due to their containing multiple adjacent megacities. At the end of this essay, readers will find a link to a fascinating interactive version of this essay's maps that allows them to explore the population mountains near their home and around the entire world.