It might look like something straight out of a sci-fi movie, but these images actually show an ancient practice that was created on Earth.
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The state of Meghalaya in northeastern India is one of the wettest areas of the country, with the village of Mawsynram reportedly the wettest place on earth. With an average rainfall of 17,800 millimetres per year, monsoons deluge the area, making man-made constructions difficult to maintain.
Which is where the Indian rubber fig tree (Ficus elastica) comes in. For centuries, these trees have helped the local Khasi people stay connected, managing to overcome swelling rivers and near-constant rain.
It's not an easy task, however, and the bridges take years and years to construct. They also need to be maintained, which can take the work of whole families or villages.
As well as being robust in the face of difficult weather, the root bridges help to halt soil erosion and absorb greenhouse gases. Ficus elastica are considered particularly important for the wider ecosystem.
It is thought that 50 or more people can cross mature bridges, which have a lifespan of hundreds of years.
These bridges featured in BBC series The Green Planet in 2022. Speaking to BBC Wildlife, producer Elisabeth Oakham said, "Concrete and wooden bridges don't last very long, so the local Khasi people have learned to create bridges from living fig trees to safely cross.
"They plant a tree on the riverbank and train its aerial roots to the other side, where they take root and 'woody up'. It takes a human lifetime to get to the point where it's a structure that adults can walk on, but then they last for hundreds of years."
It's not just bridges that the Khasi create out of these trees – there are football viewing platforms and retaining walls too.
This double decker bridge is in Nongriat village, and the team filming The Green Planet had to trek down 3,000 steps to get there and hiked the route five times.
