How do you cram 100 years worth of population growth over 590 cities into a single visual? Barcelona-based Bestiaro does it beautifully, integrating nifty web-based interactive elements. The flowchart runs on an application called Impure, the product of five years of interactive visualization research.

On first glance, this flowchart may look like one chaotic rainbow orgy of lines. However, it becomes addictively fun to explore as you discover more and more trends among the layers of information. The cities are cleverly colour-coded so that world regional trends are easily picked out. Mouse rollovers give you city names, while mouse clicks give more detailed city information.

This interactive graphic provides an easy and comprehensive tool for understanding world population growth since 1950 and projected to 2050, such as the sustained population surge in developing megacities.