“ A Deity of some sort has unleashed a plague of bookworms or something like that in the area. Almost all spellbooks are destroyed, along with bardic and historical books.”
“ A certain patch of forest is well known for causing anyone who ventures into it to suddenly go blind. Once they leave the area their vision returns. Rumors of treasure hidden within.”
“ The Yugzhee, or 'hedgehog-people', guard a great, secret treasure inside their giant burrowed lair. The mysterious Wall of Keys, a 12'x10', foot-thick, cold-iron, 'wall', upon which, on iron hooks, hang 100 ornate iron keys of all shapes and sizes. Each key opens some heretofore un-openable barrier, door, or gate, in the particular game world of choice.
The PCs have come upon a great boon, except for the fact that the keys cease to function properly if separated from the iron wall for more than a few minutes. Higher level characters will be able to figure out how to take the wall 'with them' via magic. Lower level characters will have to get creative.”
