Terragen has an option to drop spherical objects into a landscape, which I feel is a bit surreal all by itself. But I had to post-op the images to get the views from behind to shine through them. It was fun. Still pretty surreal. Maybe they're an alien artifact of some kind; either visiting, or local, as suggested by the big crescent moon hovering overhead... I used the same technique for a fanzine illustration, called Away Team.
Here's another image, slightly more...whimsical, I guess. I also called it Spheres, but had to give it a different file name for this iteration. The spheres involved are the big moon, the dome at the left (the only object applied using the same technique as the top image), and the bouncing copper doohicky at the right. All, of course, involved with the really big planet (presumablyspherical) on which this shallow ocean extends to the horizon.