Curse those greedy delvers! But what with? I know! How about Aurophobia, fear of gold? Or Barophobia, fear of gravity? And I can hit that annoying wizard with Bibliophobia, no more spells for him!
The TRUE origins of Magic, and dont even get me started on Prophecy.
A large river that is continuously covered in a thick layer of fog. There will be either a rope ferry to get across or possibly a boat that is rowed across by worshippers of the water elementals. It is very thick fog to the point where it even muffles voices even at close range and visibility even beyond a foot is almost impossible.