Dungeons/Manifest/Corrosive Nightmare/Brainstorming

Dungeon

 * Many deceptively mundane or innocent things turn out to be very dangerous
 * damage
 * conditions
 * infections
 * Note: remember to offer stat saves for them!
 * Give other party members chances to assist/save the afflicted player!
 * Make the  environment  dangerous
 * Remember to make the place horrifying
 * not as much on first impression, but initially with events rather than appearance (but gradually more with appearance)