A report by Andy Dickenson
David Attenborough has said it's 'perhaps the most significant conservation initiative ever', while Prince Charles has likened it to a gold reserve.
2.4 billion seeds are stored at the Millennium Seed Bank from 190 countries. An insurance policy that's already been used to restore land lost in Australian bushfires.
Like so much of the world right now the seed bank itself is off-limits. It's vaults flood proof, bomb proof, radiation proof - well versed in emergency.
Among its riches, a wild relative of the carrot that could help create a new species tolerant to climate change, and a flower extinct after landslides on its island in the Pacific.