This is one of the impossible figures that I myself feel works a bit better as just linework. This might be because the figure looks bent with the gradients, so the lines only version looks more clean, which is without saying really. Still, colors give volume and makes things look nice.
Complex
2009-01-28
Linework | Fillwork
Both the tower and the wings transform from one end to the other. What was in front goes behind, what was a solid turns into air, surfaces from different structures melt into a new single one.
Kyuubimode7 on 
Lee R Vander Baan on 
May we use your wonderful picture on our school project website assignment?
-Marco
Ah, that should probably be fine. Just wondering what kind of assignment is it? Does it have to do with optical illusions or do you just need some sort of logotype? :)
Thanks, our assignment is about optical illusions and topics such as reaction and what is an optical illusion. I will be planning to use your picture as an example of 3d impossible figures.
-Marco