Will says there's only 6 possible combinations for landscapes with a clear foreground, middleground, and background. You're gonna have light, medium, and dark tones, so there you go.
I'm working on some lighting keys for the cave layout, so I whipped this up quickly to give myself a basic schematic of what the different possibilities are (not accounting for unnatural or unusual lighting situations--lanterns, fairy dust, etc.)
Mostly for me but also for you to see how one layout can look so different...tone really matters!
FYI if you really want to see the difference, I'd suggest opening the image in a new tab, zooming in, and then focusing on each different layout. Looking at them all together boggles the mind...