With regard to the plot "Sleeping Mines of Elathon":
You manage to get the water wheel in the mine working which operates a pump to clear the flooded lower levels. As you explore the dank tunnels of the lower galleries, you can hear the creaking of the wheel above. You enter a low-ceilinged passage and are crawling on your backs, when the creaking stops. The water starts seeping wetly around the back of your head...
A large forest which is the site of a research monastery dedicated to Silence. In the course of developing new spells, the monks frequently deaden all sound in huge areas of the forest, an extremely eerie experience for anyone passing through.