India's Living Root Bridges
The Khasi people live in the Indian state of Meghalaya, in one of the wettest regions on Earth. To cross the many rivers in the area, they've devised a way to grow their own bridges using the secondary root system of Ficus elastica trees. Some of these bridges stretch for more than 30 meters (100 feet).
from Atlas Obscura
Key Facts In This Video
The Cherrapunji region in India is one of the wettest places in the world. (0:09)
When directed through hollowed-out logs, the secondary roots of the Ficus elastica can grow into strong bridges. (0:30)
See a "double decker" root bridge: (1:20)