17 Tymor
117 Pennod
Secret History - Season 14 Episode 4
With access to the first nationwide survey and state-of-the-art drones mapping the Great Wall of China, this documentary offers new evidence that reveals its extraordinary magnitude, rewrites its millennia-long history and decodes its complex signals system. Using cutting-edge chemistry, the programme also finds out what has kept the wall standing for so long - a simple cooking ingredient found in kitchens across the world.
- Blwyddyn: 2017
- Gwlad: United Kingdom
- Genre: Documentary
- Stiwdio: Channel 4
- Allweddair:
- Cyfarwyddwr: Nick London
- Cast: