That's right - nearly 4 billion people live inside the circle on this world map, including 22 of the world's 37 megacities.
The ranking of the world's tallest buildings has shifted dramatically since the start of the 20th century. See the evolution of this list over nearly 100...
These four maps tell the story of Chinese trade dominance and ambitions. See how Beijing's sphere of influence is rapidly changing.
These visualizations show how the tallest skyscraper of 2015 compares to other years, as well as other buildings completed last year.
Rapid urbanization is creating a vastly different world. These maps show the world's fastest growing cities, as well as how things have chanced since 1950.
In the old days, speculators would follow the gold rushes. Now, it's emerging markets that provide the big chance to become the next centimillionaire.
With China's slowing growth, and India lost in a maze of bureaucracy, who can we rely on as the emerging markets of the future?