Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4050080.
#UPDATE
###12-16-2019 V2 files added and now there are stairs. It should also be noted that since I made this for a 1" x 1" grid, I designed it in inches. If you are going to try to slice and print this, you need to scale it such that the longest dimension (29.4" is scaled to 746.76mm). I may go back at some point and re-do the files in metric but I really don't want to do that right now.
I had so much fun with the Trollskull build that I decided to take a stab at making a building myself. I will add the other floors to it eventually, but this gives the main layout of The Yawning Portal. If anyone could suggest how to get textures on things like the ring and floors, the knowledge would be appreciated.
I have added the Fusion 360 file and a SketchUp file as well.