Philadelphia's Academy of Natural Sciences contains fascinating exhibits that explore the environment and the creatures that make (or made) their home on Earth. Among the 17 million specimens in the academy, you can see a skeleton of a Tyrannosaurus Rex, pet a snake, watch live butterflies and inspect fossils. Just a few steps away is another famous Philadelphia attraction: The Franklin Institute Science Museum. It's easy to see why it is one of Pennsylvania's most popular museums, with its awe-inspiring interactive exhibits. Walk through a giant heart as if you were a blood cell, engineer a 350-ton locomotive, or don an astronaut's suit and collect moon rocks. Make sure not to miss the movie showing at the Franklin Institute's magnificent Tuttleman IMAX Theater.
While you're in Center City, stop by the unique Mütter Museum, part of the College of Physicians of Philadelphia. It showcases fluid-preserved pathological specimens, medical instruments and rare artifacts. During a visit you can see conjoined twins, the skeleton of a midget, a gigantic colon or the brain of an epileptic. The museum is not for those with weak stomachs, but the unusual displays are incredible.