Philadelphia Zoo (3400 W. Girard Avenue) announced today the return of the famous Zoo Key and talking story books, plus the addition of a new, limited-edition Dino-Key. Back by popular demand, the animal–shaped Zoo Keys will be able to be used at solar-powered audio boxes situated around the Zoo campus. Beginning March 25th, guests can use their Zoo Keys to unlock all new stories and secret tales about the magnificent creatures living at the Zoo. The new Dino-Key will unleash amazing stories of when dinosaurs and other massive creatures roamed the Earth in prehistoric times. Zoo-goers can listen to all audiobooks in both English and Spanish. Zoo Keys will retail for $3.00 and be available at any Zoo retail location and the Zoo shop.