Agency HQ is a setting in Metal Shadow Prelude. It is the headquarters of The Agency; an underground militarized research facility located on Northwest Coastal. It self-destructed at director Niccoli's command, taking all of Coastal with it..

Entrance had to be authorized by Agents above ground. The only described entry route was a two-stage elevator starting on the surface and pausing in a regal-looking black lobby underground. The elevators had transparent walls so passengers could view the levels they were passing.

The base had over a dozen levels, each used for training, grooming, and relaxation by Agents, as well as the storage of weaponry and side research by scientists. The bottom level held the director's office; a hidden level below that, the airships he was apparently experimenting on.