Venice is sinking very slowly -only about two inches every 100 years. But worse, the Adriatic sea is rising around Venice as well. A proposed plan to save the Italian city involves "inflating" its porous foundation with sea water to raise the whole town about a foot. Forty billion gallons of water would need to be pumped! Read more about the plan at National Geographic News. Link -Thanks, Marilyn!

(Image credit: Jim Richardson/National Geographic)