Philadelphia's Eastern State Penitentiary is considered the first ‘modern’ prison — the place where solitary confinement was invented. Opened in 1829 — and added onto over the years — this building provided each prisoner with an individual cell equipped with heat, flush toilet, skylight and private exercise yard. More than 300 prisons around the world followed the building's design and method of handling prisoners, which came to be known as the Pennsylvania System. Initially, prisoners were forbidden to speak to each other and were hooded when not in their cells. Cut off from all human interaction prisoners often went mad — so the policy of absolute solitude was eventually dropped.

Eastern State continued to house inmates until 1971. The prison sat abandoned until the mid-1990s when it was opened up to the public as a historical site. It is now a beautiful but haunted ruin.

[James Mundie's photographs of Eastern State Penitentiary]