The Watch Vaults of the Underlands were a one-time solution to guarding Underland breaches from the Orrish into the lands of light. Few of these were made, they were expensive and dangerous. Located inside the exit points for the breaches, they were super fortified and those who manned them were paid well to essentially be bait.
These locations have a World Watcher Edifice as a standard part of their functioning.
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Information Sources: Mundane Reference | Associated Phenomenology Only | Specific Lore
The Watch Vaults of the Underlands were a one-time solution to guarding Underland breaches from the Orrish into the lands of light. Few of these were made, they were expensive and dangerous. Located inside the exit points for the breaches, they were super fortified and those who manned them were paid well to essentially be bait.
Expensive to make, Druids had to be used to find water sources, and engineers build walls and buttresses inside the large exit points for the breaches. Advanced stone working and summoned elementals were put to work making these.
Trapped Stonework: These employed Ducateon and dwarven traps and shifting passages and floors. Even drop and swing stones with return cranks were employed to stop and isolate broken access point or squash scouts as they moved through the area. The buttresses were warded to provide protection against sappers and miners trying to tunnel under. Single individuals would not trigger them, but they were meant to slow down or trap large numbers.
When they worked, they were able to contain thousands of raiders with only a couple hundred soldiers for weeks at a time. Some even suffered multi-month sieges, creating time for a large defense force to be brought up.
These employed Light traps to bring daylight in. Polished mirrors on swivels channeled and amplified daylight from the outside into entry points to prevent easy overruns through the entry portals to the defenses. Sometimes they had mechanisms to even bounce it into the caverns where the Orrish were.
Trapped Stonework: The ledges holding ranged combatants behind the interior walls were often bobby-trapped to collapse if overrun. The stairs up to them were also known to be warded and trapped.
Trapped Stonework: Escape holes into the celing were said to lead to stones that could be dropped on masses moving below. These were concealed to look like a rough part of the celling and operated from holdout positions.