|A black structure stood in the center, a jagged ziggurat of sorts. Through its porous edges, beams of light shot out and pierced the thick black void around it. On the furthest edges of the frame, thorns and the shadows of indistinguishable monsters loomed.|
|- Eljunbyro, ch. 68|
The Midnight Armory is an impenetrable fortress on the dark side of the world. Luna explains that "...its presence there protects two things: the Harmonic Prism and the tranquil balance of the entire world." As the last known location of the Harmonic Prism, reaching it is the main objective of Rainbow Dash's quest.
TODO There's a big dump of info in Utaan "In Front / Open Large Doors" to cite.
According to Luna, the Armory was designed to keep the Prism secure, and to serve as a beacon to bring light to the dark side of the world while warding off the chaos creatures that may seek to exploit it. The Armory was also designed to be impregnable to any mortal creatures. Opening it would require "the simultaneous concentration of multiple immortals"
A stained glass window in Canterlot depicts the armory a black, jagged ziggurat, emitting beams of light into the thick void around it. Luna and Celestia describe it as having 4 entrances, one in each cardinal direction, that are attuned to harmonic energies.
- ↑ Ynanhluutr ch. 25