Mass Effect Citadel
The Citadel, from Mass Effect. Some artistic license taken with the design, but I think it's fairly faithful.
Had a catastrophic accident while setting up to take a WIP photograph--this thing isn't exactly very stable. Frustration led to a marathon session of building out the wards and fixing the ring, and before I knew it I was pretty much done. Thanks for giving me a nudge, Peter.
Shot in low light with two blacklights to make the trans-neon-orange elements fluoresce. I'm not completely happy with the nebula I threw together, but what the hey--I think it looks cool.
I will most likely take more photos, but I wanted to get something posted while the thing is still intact. :>
Primary reference picture.