The Vine Bridges of Iya Valley
One of Japan's three "hidden" valleys, West Iya is home to the kind of misty gorges, clear rivers, and thatched roofs one imagines in the Japan of centuries ago. To get across the Iya River that runs through the rough valley terrain, bandits, warriors and refugees created a very special - if slightly unsteady - bridge made of vines.
This is a picture from the 1880s of one of the original vine bridges.
Some people believe the existing vine bridges were first grown in the 12th century, which would make them some of the oldest known examples of living architecture in the world. But there is one ancient group of peoples who took the concept to an entirely new level.