In Northeastern India bridges are created in a unique way. Its one of the wettest places on earth covered,humid with mountain streams and rivers which provides an optimal place for trees to grow.
A type of rubber tree called the Ficus elastica is grown and molded into living bridges.
Some of the bridges span more than 100 ft long and can hold the weight of more than 50 people at a time.Some have taken 10-15 years to grow. But since they are living they are always growing and actually get stronger with time. Some are thought to be more 500 years old
The bridges are created by the Khasis using betel nut trunks. the trunks are sliced down the middle and hollowed out The roots from the tree grow into the trunks growing straight out. When the roots reach the other side they regrow into the soil there.
Locals have kept the bridges from being destroyed and replaced with modern steel bridges. In fact they are still growing new ones today.