A skill passed on from generation to generation and a process that can take decades to finalise the Living Root bridges of Cherrapunji are one of the best examples of ancient sustainable design i have ever seen. They form a network of bridges The War-Khasis tribe use to cross rivers in what is the wettest place on earth.
In order to make a rubber tree’s roots grow in the right direction – say, over a river – the Khasis use betel nut trunks, sliced down the middle and hollowed out, to create root-guidance systems.
The thin, tender roots of the rubber tree, prevented from fanning out by the betel nut trunks, grow straight out. When they reach the other side of the river, they’re allowed to take root in the soil. Given enough time, a sturdy, living bridge is produced.
As the bridge is ‘Alive’ and continually growing it gains strength over time, there is also no absolute design which i think is what makes these bridges so beautiful, some being over 500 years old clearly have a clear visual story to tell.