Federal officials visited a correctional center in Thomson, Ill., on Monday, to see if it might be appropriate for housing detainees from Guantanamo Bay. A statement from the governor's office described the prison as a "virtually vacant, state of the art facility." What makes a prison "state of the art?"
A triangle shape, in part. Modern prisons are generally designed with three sides, no more than two stories of cells lining the perimeter, and communal activities like dining in the center. The shape supposedly allows guards stationed in the middle to see every corner of the building, with better sight lines than you'd get from a rectangular layout. (The triangle design came into fashion in the United States after World War II and soon spread to other countries.)