National Geographic Documentaries
National Geographic Documentaries
Earth's Giant Hole (2012x31)
Data emisji: Lis 21, 2012
Professor Darryl Granger explores China's tiankengs - giant natural holes, hundreds of metres deep, which have developed in unusual environmental conditions.
- Premiera: Wrz 1965
- Odcinki: 859
- Obserwujący: 39