Double Decker living tree root bridge, Nongriat Village, Meghalaya, India.

* The living bridges of Cherrapunji, India are made from the roots of the Ficus elastica tree.
* This tree produces a series of secondary roots from higher up its trunk and can comfortably perch atop huge boulders along the riverbanks, or even in the middle of the
rivers themselves.
* The War-Khasis, a tribe in Meghalaya, long ago noticed this tree and saw in its powerful roots an opportunity to easily cross the area's many rivers. Now, whenever and wherever the need arises, they simply grow their bridges.
* 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 root bridges, some of which are over a hundred feet long, take ten to fifteen years to become fully functional, but they're extraordinarily strong - strong enough that some of them can support the weight of fifty or more people at a time.
* The Cherrapunji region is one of the wettest places in the world with many fast-flowing rivers and streams, making these bridges invaluable to those who live in the region.
* Since they are alive and still growing, the bridges actually gain strength over time - and some of the ancient root bridges used daily by the people of the villages around Cherrapunji may be well over five hundred years old.
* Some can take ten to fifteen years before they are fully functional.
* One special root bridge, believed to be the only one of its kind in the world, is actually two bridges stacked one over the other and has come to be known as the "Umshiang Double-Decker Root Bridge."