In terms of inspiration for an RPG, need I say it again?
The Monastery of the Unsleeping Ones
If that does not inspire a desire to go and try your hand at a megadungeon, I don’t know what will. For those of you who are uncomfortable with using a name of an actual monastery that produced saints, know that history has not only seen invaders close down the monastery, but there are plenty of examples throughout history of various governments aggressively destroying monasteries (King Henry VIII, for example).
When it comes to conflicts between church and state, monasteries have historically been hot beds of opposition. It is therefore a natural inclination of the tyrant to wipeout this opposition.
Thus, the back story of the monastery need only answer two questions and still pay homage to the original:
- In a world of monsters and sin personified, what were the monks protecting the world from with their constant prayer? Is there a gate kept closed by the monks? Is some cthuloid horror bound somewhere beneath? What other monsters were kept dormant? Were the monks the equivalent of a Sussuruss that kept an army of undead asleep (and therefore add another meaning to the name Unsleeping Ones)?
- What prompted the closure of the monastery? Did a king come into conflict with the monks over doctrine? Was there an invading army that had no idea what lay within? Did some evil specifically seek out what the monks were guarding against?
Answer these, and all one needs is a good map and a willing group of adventurers...