The castle-like Eastern State Penitentiary is one of Philadelphia's most important historic sites. Having opened in 1829, this Quaker-inspired prison sought to reform prisoners using isolation and reflection rather than capital punishment and physical abuse. Although it was shut down in the 1970s, the Eastern State Penitentiary led the way to reform in the judicial system. Today, you are welcome to tour the facility; the highlight for many is Al Capone's cell. 

Bear in mind that this attraction may not be appropriate for younger children due to its rather frightening nature. Recent visitors said the site is intriguing, yet disturbing, if not downright creepy. To  embrace the terror, visit around Halloween when the prison turns into a haunted house with six different attractions. If you do decide to bring the kids, the Eastern State Penitentiary offers family-friendly tour options with a more PG retelling of the events that took place behind its thick stone walls.

The Eastern State Penitentiary is located several blocks east of the Philadelphia Museum of Art. The penitentiary is accessible via Philadelphia Trolley Works, Big Bus, The Phlash, Philadelphia Bike Tours, and several SEPTA bus routes. It is open to the public every day from 10 a.m. to 5 p.m. with last entry at 4 p.m. Admission (which includes an audio tour) costs $14 for adults and $10 for children ages 7 to 12 if you purchase tickets online. In person, there's an additional $2 fee per ticket. There is also a daily guided tour at 2 p.m., but you must reserve a ticket in advance (no additional charge). For more information, visit the former prison's website.