A Dash of Boulder
From A KoL Wiki

In the Dungeon of Doom, you encounter a hallway blocked by a huge boulder. You push and push and push, but eventually reach a dead end, at which point you have to just turn around and leave.
You'll always wonder what was at the end of that corridor.
Occurs at The Dungeons of Doom.
References
- The adventure title and text may refer to the video game Boulder Dash, in which your character pushed boulders around.