panopticon, architectural form for a prison, the drawings for which were published by Jeremy Bentham in 1791. It consisted of a circular, glass-roofed, tanklike structure with cells along the external wall facing toward a central rotunda; guards stationed in the rotunda could keep all the inmates in the surrounding cells under constant surveillance. Although Bentham’s novel idea was not fully adopted in the plans for penal institutions built at that time, its radial plan was immediately influential, and its design clearly had an impact on later construction. For example, the Stateville Correctional Center, a prison near Joliet, Ill., U.S., incorporates essential features of the panopticon.