Any Old Port in a Storm
The PCs are seeking shelter from the elements or some other threat, and come across a place to hole up. They find that they have stumbled across something dangerous, secret, or supernatural, and must then deal with it in order to enjoy a little rest.
Common Twists & Themes: The shelter contains the cause of the threat the PCs were trying to avoid. The shelter houses a Hidden Base (q.v.). The PCs must not only struggle for shelter, they must struggle to survive. The place is a legitimate shelter of some kind, but the PCs are not welcome, and must win hearts or minds to earn their bed for the night.