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How high can we build?

Play this 60-second animation to see how tall buildings have changed over the years, and to see how high future plans will take us.

Source: Halcyon Maps, Popular Mechanics.

Learn more about this topic:

Which cities are the world's largest and where are they located? Play this 60-second animation to find out.

Where are the largest cities?

In this series for secondary schools, some of Britain's most iconic and secretive engineering companies reveal how they build the world's most amazing machines.

How to build....

Photography has preserved moments in time and unmasked great mysteries. Here's 16 of the best.

How did 16 photographs change the way we see the world?