I'm very convinced this Underdark City can actually be made in NWN2 and done justice in the attempt. The lower level is partially walkable but my planning skills suck so I didn't think to make a building hotspot and leave the rest plausibly unwalkable / unreachable.
Right now the walkways leading to off map ends are made unwalkable and some stuff was put beyond the borders to make the city look big.
I'm going to put all the landmarks of the lower level in a central hotspot which isn't very connected to the rest of the city. Then make those connections unwalkable. Include a few residence platforms you can reach but leave most as horizon filler.
I haven't started the Top level yet but it should have a proper Temple of Lolth, some warehouses, a tavern and probably some other stuff. Oh and the major houses of Ched Nasad.
The middle level is mostly placeholder stuff to see how it looks with multiple levels. (awesome)
http://imageshack.us/f/411/chednasad.jpg/ (big)
