Here’s a quick map I drew the other night. I used metal nib and India ink in a bottle. Colored it in with Crayola pencils.

I imagine this as a sacred burial chamber with monoliths arranged in a pattern. Primitive man would bring their dead here and place them within the circle. Niches in the walls could hold some of the tools and weapons the warrior used.

Those entering the cave will first come upon a standing stone. It is taking up much of the space in the corridor. All who enter must squeeze past it on either side…symbolic of passage into the underworld?

There’s much more I can add to this, but as it is, I may drop the image into our Roll20 game.