The Forgotten Entrance to Felltower (not really)

One of the entrances to Felltower was through a poison ivy covered hole in a foundation wall. It's gone disused because it's a terrible entrance for most purposes and it's a terrible exit for all purposes.

It doesn't quite look like this, but this kind of claustrophobic crack that I saw today on a walk could easily have been that entrance:



After all, why shouldn't big dungeons have small, really unpleasant tunnels that lead into the inhabited portions? Not that the small, really unpleasant tunnels should be inhabited. Or untrapped. Or safe in any way.

Of course, given player's estimations of difficulty, someone is going to claim they can crawl into that with their Medium Shield ready, rapier in hand, and be able to Retreat when attacked. My answers would be ha, ha, ha.