# Survey Bunker

A hatch-and-ladder shelter left by the Halcyon Survey: a ladder shaft down to a hub chamber, a few
corridors and rooms, one sealed vault and the Survey's logs. On Earth it is where the story starts.

## Where it generates

- **Earth (overworld):** dry land — plains, meadows, deserts, forests, taigas, savannas, badlands and snowy
  plains. Rare: in testing the nearest bunker was usually 1.1–1.2 km away; over ocean it can be much
  farther.
- **Every moon and planet** (with Nerospace): more common than on Earth.
- Sites must be dry and reasonably flat. The hub sits deep enough that rooms stay buried on a slope.

## What you find

- A hatch on the surface and a ladder down into the hub. One hub layout of three is chosen per bunker.
- Corridors (straight, long, turns, a junction) leading to rooms: store, lab, service, canteen and archive.
  The archive room has a Log Terminal.
- Satellites near some bunkers: a fallen or standing antenna, and a supply cache.
- Chests with salvage, supplies and Earth data shards.

## Puzzle and vault

The hub holds a **Vault Cache sealed by three or four Ballast Plates**. Each plate shows how many items it
needs; load every plate exactly to unseal the vault. See [Puzzles](Puzzles.md).

## Guardians

A **Ruin Spawner** is set into the hub floor; its range covers the ladder foot, every plate and the vault,
so you cannot reach the vault without waking it. Arc Grates lie in some corridors. See
[Guardians](Guardians.md).

## Protection

The bunker has no separate gated room, so its hull is mineable. The vault, plates and spawner are
unbreakable, and the vault stays sealed until its plates are solved.

[Home](Home.md)