What are the most beautiful bridges ever built?

I nominate the living root bridges in North East India.How these bridges are constructed.. The development and upkeep of bridges is a community affair.  Initially,  a length of bamboo is secured across a river divide and a banyan  plant, Ficus benghalensis is planted on each bank.  Over the months and years, the roots and  branches of the rapidly growing Ficus are trained along the bamboo