Wait. So the blue door is the entrance to what's inside the crater, and the crater is the ring of mountain that can be seen in the far background and near foreground? Wouldn't that be more like a mountain INSIDE of a crater? I may be overthinking things, but I think that's what I'm seeing now that you pointed out the ring of mountains.
I wish I had meaningful things to say, but I'm not that knowledgeable of the arts. Really nice looking picture! I love the colors and the feeling of fantasy it gives.
There's one little area that looks off to me because it looks like there's a straight line going up. Like, the colors just suddenly end and drastically change. Dunno how to point that area out with text though.