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.
I feel honoured to work here and with our partners around the world, meeting these passionate and engaged people who really want to make a difference for the world of plants on this planet. But the actual value of the seeds we hold here, at this time of biodiversity crisis, you can't put words to describe how important those are.
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.
Having the Millennium Seed Bank here connects us into a global conservation programme, it connects us into everything that is vital about plant science right now - this realisation that we are losing biodiversity at an alarming rate, and we are also able to do something about it.