An ancient stone temple built by Orum himself eons ago when the arch-demon fully manifested and gained sentient conscience. The temple's many chambers and atriums was purposely built as a redundancy mechanism in the event of a temple breach, giving his army time to assemble and counteract whatever threat that manages to make it inside. Though now the arch-demon has perished and ruin has washed over his realm, his temple still stands, seen as a sign of continual defiance even in death by those who survived him. It's robust structural integrity is due to the massive amount of stone implemented in the design, as well as Orum's own power left behind in the form of his crystal eye.
Sanctum of the arch-demon Kabronon. As the arch-demon began fully manifesting, Kabronon acquired an extraordinary control over manipulation of temperature and elements. Upon forming his own realm, he filled it with his armies before casting a deathly chill across the land. The cold was enough to sap the strength of the strongest who wasn't adept in countering ice elements. And the freezing chill imbued his soldiers' defenses, making them nearly indestructible.
Over time, the other arch-demons soon learned how to use manipulative powers to their own means, and managed to counter Kabronon's freezing chill. Before he was slain, he channeled the last of his power into his horn that lays abandoned in his chamber.
Realm of Lilith
A private dimension created solely for the purpose of Lilith's own personal recreational use. Her creator, the arch-demon Narsonah gifted it to her after Lilith's creation, as well as the crystal weapon Doh'kuun for her to use in the wars alongside her brother, Daath. Using the power of Doh'kuun's crystal, Lilith turned her realm into a sprawling network of channels and portals to other realms, threading their troops to warfronts all across Agroedon.