First off, I really like the epic feel of this place. The storyline no sacred cow for me since I don't know it well but even if I did I never play canon, especially if the players know the canon. Then it has to change to preserve the suspense and emulate the in-world ignorance of the PC's. The twist of the archmages does that here for me.
But that's kind of getting off the point. The flavor draws you in to this awesome place which at first seems so strange but becomes almost iconic in its oddity. A black lake with a strange island in the center, with otherworldly earth (nice choice) elementals doing cthonic things with bad geometry. It's really interesting. As a modder I can easily envisage using this location in other ways: if I didn't want a time bomb scenario, I'd have the PCs visit this place when the Xorns are trying to convince party spellcasters to help them complete arcane rituals to restore the Conduit. Good opportunities there for sense motive, arcana/knowledge(religion),or language use, and combat or diplomacy routes. And that's just mining one of the nuggets all over this map - the Xorn den.
The map itself is very cluttered. It's a microcosm of the bad geometry of the conduit. And it would have been nice to see some comments on what backup plans exist if the conduit does get stopped. I know it's probably "continue fighting" but some twist would have been welcome there, especially for a very melee-oriented party. Perhaps a magical item intended as a tribute to the expected earthlord, now in rage converted to a one-time use weapon.
But these are forgivable for a very beautiful place - one not just destined to be used and moved on from. I couldn't disagree more that one location shouldn't have such strong backstory implications. Not all of them can but when you make one, it becomes memorable on many levels - for what happened there in the past, for what you went through there, and for what it's like to revisit or just to have as a unique set piece on the stage of your campaign.
Recommended for advancement.