Galactic Seed Vault

The  was a facility on the ice planet Calufrax Major for storing and preserving samples of plant seeds from across the universe in case of a global cataclysmic event.

Location and appearance
The vault was situated at the base of the tallest mountain in a polar region of the planet. The building was grown rather than constructed and, consequently, had wood in its structure.

It was a black angular, wedge-shaped building constructed from light-sucking material. Its visible part was 200 metres high and approximately 50 metres across. The building extended deep into the mountain. The vault was connected to the mainland by a narrow metal bridge without guardrails stretching over a deep chasm.

Drones were sent and returned to the drone hangar, a launch-and-retrieval bay. The retrieval section with a conveyor belt enclosed in a sealed transparent tunnel was at the far end. (PROSE: The Secret in Vault 13)

History
The Galactic Seed Vault was created by the First Gardener with the help of Time Lords. It was considered one of the most secure buildings in the universe. In particular, it had ground-to-air defences.

Visitors were not allowed, to prevent the risk of contamination. Seeds were collected by automated seed-collecting drones the size of a bird, which sometimes sought a particular seed for a thousand years.

At some point thousands of years before the visit of the Thirteenth Doctor, renegade Gardeners who preceded Nightshade by ten generations smuggled a weaponised seed into the vault.

At some point several thousand years before the visit of the Thirteenth Doctor, four plant-hunters broke into the vault to source seeds for a private collector. They did not make it past the first level of security. Several months later pots with their remains in the form of compost were delivered to each of their home worlds. (PROSE: The Secret in Vault 13)