I’ve visited Philadelphia several times over the last few years, and when I first saw the Eastern State Penitentiary, I was immediately drawn to its imposing walls. On each visit, either because of weather or my schedule, I wasn’t able to venture in.

On a visit to Philadelphia last October, I told myself that I just had to visit. Of course, it was damp that morning, and I thought I would once again fail to go. Just as the gates opened for the day, however, the weather improved!

Operational from 1829 to 1971, the initial design focused on solitary confinement—meant as form of reform based around a monk like notion of penance. With expansion and overcrowding, this system broke down, and eventually was abandoned.

Today, its cells and corridors are haunting.