Eastern State Penitentiary was established in 1829 in Philadelphia. The penitentiary’s unique architecture (its radial floor plan and separate cells) and stringent system of solitary confinement served as a model for over 300 prisons worldwide. Inmates were kept in isolation in individual cells with thick walls, only to be released for a short period of time each day for exercise. Each time a prisoner left his/her cell, they were shielded with a hood in order to prevent contact (both verbal and visual) with other prisoners. While some argued that solitary confinement allowed reflection and rehabilitation, others opposed the practice, deeming it cruel and dehumanizing.