Dark Dreams of Furiae - a new module for NWN:EE! Buy now
This is a difficulty spike. Don't go there below at least level 7-8 party-wise. A thief with 100 in Find Traps is a must, or with good supply of Potions of Perception.
It is a serious dungeon crawl, don't expect to rush it. Slow and tedious with danger around every corner. Enemies are quite strong the deeper you go. You will hate this place.
I am not happy with the loot, nothing spectacular so far, lots of projectile ammo and can't take all, need trip back to HQ (usually also reviving Coran) . But good XP farm.
Reminds me of DAO's Orzammar area which similarly was a difficulty spike the deeper you go. But these two games were made by the same people as far as I know.