The fifteen meters of annual rainfall of the Cherrapunji region–a figure aggrandized by frequent flash floods–accelerate the flow of its rivers and streams, the fierceness and destructive power of which few wooden or steel bridges could withstand. Transport across the region’s numerous water channels is necessary, whether to return to one’s dwelling after fishing or clothes washing or to escape the dangers of one place to move to another. But how?

The locals’ answer lie in the sloping hills hugging the contour of the water channels, where a species of rubber tree flourishes. From the upper trunk of the ficus elastica, secondary roots grow outwards with great profuseness. The tribes people realized half a millenia ago that they could use these roots to forge a pass across the water below, using hollowed out betel nut trunks to guide the direction of the roots’ growth.

-Via Notcot