Why was the Great Wall of China built?

The clouds we see in the sky seem rather light, almost like absorbent cotton. However, being filled with water and ice, these gigantic suspended masses weigh - in reality - up to several tons. Don't be fooled by appearances, the clouds that float above your heads are more like an ...  Show more

Long before Magellan completed the first circumnavigation of the globe, in the 16th century, ancient Greek scientists had demonstrated, by simple observation, that the Earth was round, or rather spherical. Of course, this did not prevent some people from believing that our planet ...  Show more

The Great Wall of China is one of the architectural wonders of the world. Stretching for over 21,000km - as far as London to New York and back, twice - it follows what used to be the border between China and Mongolia. Built over a period of 2,000 years by millions of conscripted ...  Show more

The Great Wall of China is one of the architectural wonders of the world. Stretching for over 21,000km - as far as London to New York and back, twice - it follows what used to be the border between China and Mongolia. Built over a period of 2,000 years by millions of conscripted ...  Show more

It's one of the most iconic structures in the world: The Great Wall of China.

But is it just one wall? And who built it and why? Today, Tristan Hughes is joined by William Lindesay OBE to delve into the ancient history of this epic structure and to answer these quest ...

The Great Wall of China is one of the most visited tourist desinations in the world. How'd it get built? How old is it? What's the current condition? Learn this and more in today's episode.