~3 weeks. SketchUp, Photoshop.
3rd in Gnomon Contest. June 2012: Temple Ruins [link]
I been painting this here and there for about 3 weeks for a Gnomon Workshop contest. The goal was to practice a new technique where I start the image with a line drawing made in Google SketchUp (solely for accurate perspective), then to do do everything else in Photoshop. I didn't have time to finish it, but I'm calling this one finished.