The Root Bridges of Cherrapunji

Root bridges have also been made by creating scaffolds out of wood and bamboo, and then training the young roots out across these temporary structures, replacing the more perishable elements many times as they rot in the intense monsoon seasons. The root bridges can grow for as long as the organism they are a part of remains healthy, though they can take many years to initially become functional, the length of time being dependent on local conditions such as the health of the tree, the way the bridge is being grown, and the availability of nutrients in the soil that its being grown in. In fact, because 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 500 years old.

Source: www.atlasobscura.com