House of Correction (Philadelphia)

Planned to incarcerate misdemeanants, the House of Correction was built without perimeter walls and without observation towers. The design of the facility is based on the "wheel-and-spoke" design first seen with the construction of Eastern State Penitentiary in 1829. A central rotunda provides access to six two-tiered cellblocks, which radiate from the rotunda like spokes from a wheel. The cellblocks contain a total of 663 cells, most housing two inmates.

- from the Philadelphia Prison System website (207.36.233.204/prisons/)