You could easily spend the better part of the day touring this world-class science museum. As well as being the venue for temporary blockbuster science exhibitions, there's a planetarium, IMAX cinema and great permanent features such as a giant two-story replica of a beating heart where kids can crawl through the arteries.
The institute was founded in 1824 by Benjamin Franklin; a memorial to him in the lobby includes a stunning 20ft-high marble statue in a rotunda modeled after the Pantheon in Rome.
The museum hosts much of the Philadelphia Science Festival each April.
