I have long advocated for a prison consisting of about 20 square miles of west Texas, far from anything. It needs two fences, high and electrified. It needs nothing else. No food, no water, no shelter. Put those convicted of really bad stuff inside the inner fence, and let them fend for themselves. Those who think they're really tough bad guys have plenty of time to prove it. If they live out their sentences, let them out. If they die, the coyotes, ants, and buzzards will take care of them.