One of the entrances from an above level, long set of stairs leads to a room (entry in the middle of south wall, no door, no landing - room is 25' north-south, 125' east-west, ~15' high). North wall is mosaic tiled. Doors on east and west wall, both are teleporters to the same location - anyone touching a door is teleported, no save.
The mosaic depicts the body of an octopus, and 4 of it's tentacles run the length of the north wall. Artistically tempered PC's may note the quality of the work, particularly the well-rendered human eyes. The octopus is depicted eating a red-haired man, half hanging from its beak. To the east forests are shown growing from its tentacles, gradually getting thicker - to the west, icy mountains rise.
Approaching the eyes brings an uneasy feeling. Should a PC stare into them for 5 minutes, roll d6, effects depend on class:
1-3 cleric/magic user: lose 1 spell casting (of highest level known), other: take d20 damage
4-6 cleric/magic user: restore cast spells, other: heal d20
"I want to be in Kentucky when the end of the world comes, because it's always 20 years behind" - Mark Twain