The Inverted Lighthouse of Sub-Ba'Sal

The Inverted Lighthouse of Sub-Ba'Sal appears to be little more than a one-story brick building on the surface.
However, the true extent of this structure is appreciated from the view beneath the earth. The structure plunges 5 stories deep and is surrounded by giant braziers that act as a warning to all of the underground flying craft. Just as a traditional lighthouse warns sailors of nearby rocks, the Inverted Lighthouse warns underground pilots of the nearby ceiling.
The lighthouse is also equipped with clear windows, along with viewing platforms and ample pairs of binoculars.
It is currently operated by various subterranean dwarven clans and is used by them as an early warning system for impending goblin raids.

Type

Lighthouse