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. The Thirteenth Doctor believed it to be alive.

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.

The inside of the vault was illuminated via bioluminescence that reacted to the presence of visitors.

The vault possessed its own internal transport system in a form of capsule-shaped vehicles.

There were twelve consecutive seed storage vaults connected by corridors, each vault containing glass pillars hundreds of metres high filled with spherical seed jars. Firefly-like insects inspected seed jars to ensure perfect conditions. The vault on one end was connected by a corridor to the control room. From the vault on the opposite side, it was possible to access the secret thirteenth vault via a holographic shield wall disguised as a cliff face. Passing through this shield required hitting it at a particular angle and velocity. (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 seed of a modified variety of noughtweed 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.

When the Thirteenth Doctor and Yasmin Khan entered the vault, noughtweed has already spread through eight seed storage vaults damaging them beyond repair. At that time, the vault stored eight-hundered-and-thirty billion varieties of plant in seed form.

Almost immediately after their arrival, the vault was captured by Nightshade and his Grave Diggers. (PROSE: The Secret in Vault 13)