Perhaps it's just my inner bibliophile rising to the top, but I recently ran across an article in the online Times of India that I thought had great gaming potential:
Secret chamber in National Library
The chamber has lain untouched for over two centuries. Wonder what secrets it holds. The archaeologists who discovered it have no clue either, their theories range from a torture chamber, or a sealed tomb for an unfortunate soul or the most favoured of all a treasure room. Some say they wouldn't be surprised if both skeletons and jewels tumble out of the secret room.
The story as-is would make a great drop in for a Pulp Action or Horror campaign, depending on whether the GM wanted to emphasize the skeletons or the jewels. Actually, a secret room with no obvious way to get in seems like it would fit perfectly in a Lovecraftian game, as the innermost sanctum of some unfortunate wizard. It's probably filled with Hounds of Tindalos or something. And hey, new idea - dial back the horror elements and you get a great set piece for a DFRPG session!
On a less specific note, the article mentions that the building the room was found in, now the national library, was originally a royal palace and then, for a while, a governor's residence. This suggests some interesting possibilities for designing, for example, dungeons for a D&D-fantasy game - that door into a corridor with no floor might have a perfectly reasonable explanation, such as a now-nonexistant staircase. And hey, what's this walled-off section in this room full of books . . . ?