It is dark. It is likely that you will be eaten by a grue. At the bottom of a long ladder, there are two passages, both alike. One goes nowhere. The other leads to a long, dark, endless tunnel.
Your headlamp is not bright enough to see very far, so you continue on into the blackness.
Suddenly, something reeks. You look around at the walls, and see this alien life form.
It lets you pass into its chamber. Sound behaves strangely here.
(Most of) our intrepid crew; Josh and Rachel wandered off somewhere, we should probably look for them sometime…
A night at the opera. This room resonates LOUD at low F#.
Aha! I found our missing adventurers
At last, the end. This tunnel is close to 10 miles long, not even counting the branch routes.
A few more I didn’t bother to post here