The Eternal Enclave

"In all my travels, I have never discovered a place as forlorn as the failed utopia, the Eternal Enclave." - Unknown
The Eternal Enclave was a settlement created by idealistic necromancers who wished to create a utopian society where they could be free to study the dark arts for an eternity, infinitely expanding the scope of Ibian knowledge. In preparation for this pursuit, the group, led by Archmage Morianus, found a suitable cave on a mountainside far away from civilization in the wilds of Ferus Frontier. In order to prevent their discovery and intrusion upon their dark rituals, they enchanted the entire mountain with concealing runes, making it disappear completely from the country skyline. Furthermore, to annihilate any interlopers who happened to stumble across their clandestine sanctuary by accident, they created an army of golems and sentries imbued with the most powerful reagents of their era. With their defense nearly impervious, the members of the enclave set about performing the necessary rituals for ascending each and every one of their numbers to lichdom so that they could then seal themselves away from the world to dedicate themselves wholly to their quest for knowledge for the rest of time.
Unfortunately, it was not long after they shed their mortal coils that the members of the eternal enclave lost interest in their lofty ideals. Their immortality was marked by idleness, and instead of the noble research that Archmage Morianus had envisioned his colleagues performing, they spent their endless time trying to distract their ceaseless consciousnesses with games and other such meaningless diversions instead. Inevitably, disagreements between individuals led to fragmentations in these gaming groups, and this trend continued until each member would only play by themselves. In their isolation, they entered into meditative trances and let their imaginations run wild, each creating and exploring intricate and fantastical worlds through their mental constructs. It was less than a decade after the eternal enclave was founded that all its members entered into such a trance; even after centuries had passed, and interlopers had managed to breach their defenses, not one lich stirred in their chamber, so absorbed were they all in their individual fantasies. 
The imperial expedition who discovered this cache of liches initially considered exterminating them before they ever had the chance to awaken and potentially wreak havoc across the land; however, the leader of the expedition deemed that there was no need to do so as they were already beyond dead.