Human: Make a concise location description of a foreboding scene outside of a cavern with phosphorescence and people. Assistant: 
The spacious ledge is large enough for many people to make camp safely, but drops away to the west in a sheer precipice overlooking an expansive cavern below. The cave stretches out farther than the eye can see in the dim shadows of deep subterranean structures and the faint glow of patches of phosphorescence below. Now and then, unidentifiable forms move in the shifting darkness, the echoing sounds of footsteps and scratching indicating that they are more than a trick of the light.