To the Valley (1/2)

Three hikers discover a very mysterious valley... which we're going to call the "valley of the tall tropical trogl-hobbits", because its (also very mysterious) past inhabitants apparently chose to carve their houses inside the rock and underground instead of building them on top of said ground like sensible people would.
I'm not going to complain, though: troglodyte houses are great.
(Part 1/2 of a private commission)