When you read in the strategy guide. in the back they put in rumors of the sunken ruins of Bal Fell under the current ones. But also stated that they were not there. But that is was what the construction set was for. so i used it for that.

posted here http://www.tesnexus.com/downloads/file.php?id=31389

Sounds fun . DLing now . Will play test in a while ( new character on the go at present ) when high enough level . What level would you recommend the player be at before starting your addition ?

well over twenty without cheating. monster level avg thirty.

i got an error with the NX9 files they seem to be not included. i dled bot files in the link.

you have to have nx9's daedra additions as well it's on tesnexus as well here is link. http://www.tesnexus.com/downloads/file.php?id=29713