It’s not Halloween without Boo at the Zoo! Join Philadelphia Zoo (3400 W. Girard Avenue) for three spooky weekends for this annual fall extravaganza! Guests are encouraged to come in costume, explore the Zoo during the beautiful autumn season and enjoy festive fall offerings for purchase. Get ready for some tricks, more treats and lots of excitement at this yearly Halloween celebration, including candy around the Zoo. Come dressed in your favorite costume, enjoy seasonal décor, photo opportunities, festive fall offerings and have a spooktacular time! As a special treat to pair with Boo at the Zoo, and by popular demand, BIG TIME has been extended to October 31st. Guests can celebrate Halloween and visit dinosaurs all in one day. There's no tricks, just treats at Philadelphia Zoo! Boo at the Zoo is free to members with advance online reservation. Admission for Boo at the Zoo is free with the regular price of admission.