The "Panopticon" was a prison so hideous that it has never actually been built in all its "glory".
It was the brainchild of Jeremy Bentham, that heartless Utilitarian philosopher. The Panopticon
"Hence the major effect of the Panopticon: to induce in the inmate a state of conscious and permanent visibility that assures the automatic functioning of power. So to arrange things that the surveillance is permanent in its effects, even if it is discontinuous in its action; that the perfection of power should tend to render its actual exercise unnecessary; that this architectural apparatus should be a machine for creating and sustaining a power relation independent of the person who exercises it; in short, that the inmates should be caught up in a power situation of which they are themselves the bearers. "
They actually built one in Lima, Peru in the middle of the 1800s. It has sense been torn down. You can see what i looked like here:
http://historiadordelperu.blogspot.com/2012/02/la-vida-en-la-penitenciaria-de-lima.html