Greetings Seeker Kor'us,
After returning to the Bowels of the Machine, I was able to locate the door that leads to the portal rooms.
I was surprised, by what I found there. It seems a few renegade Chosen have taken up residance in some of the areas of the Machine. When I first traveled through the Machine, hordes of undead and their machines only walked the halls of the Bowels of the Machine.
After a few small skirmishes, I was able to find the door that lead to the portal rooms. It is located on the stairway leading down into a room with four levers. When I first gained access to the portal rooms, the levers had to be activiated in a certain sequence, and there was a special key that was needed. It is my own theory that without these two things, if the door was open, it would lead entirely to a different place then I was before.
Though the portal rooms I speak of are small, with four floating doors set facing one another. Each room was guarded with undead and the machines. Each portal lead to a random location in the machine, or deeper into the underdark. It is some what impossible to navigate where these portals would lead, but each door was covered in runes. I believe these ruins can tell where the portal leads, though the runes where far beyond my comprehension.
The party I went with, suffered greatly and many falled in the battle. We felt it wise not to remain there any longer then needed, and we quickly made our way back to Sanctuary.
If I can remember more details, I will let you know. I do thank you for your time though.
-Kel the Broken Blade