Floating Cities Of Atlantis

I started this on Tuesday, and I knew I wanted an explosion of light at night. I messed up the layers on Gimp several times, not saving enough of my progress as I went along. Will I ever learn?

This was my starting point on Sterling2:

But then I realized I was running out of time, at one point I had around fifty layers on Gimp and I still didn't have anything I was happy with: I kept oscillating between underwater/hidden in the jungle/alien city idea. So I started from scratch again yesterday.

Finally I settled with this piece. It uses nine raw fractals created with Sterling2, combined and modified in Gimp.

This is my entry to the contest by @juliakponsford.