In countless zombies books, from World War Z to The Walking Dead, prisons are depicted as being the ultimate refuges for surviving the zombie apocalypse. The Zombie Survival Guide by Max Brooks dedicates 6 pages up it, whereas other refuges get only 1-2 pages.

While this argument holds obvious merits, I still have doubts. One obvious problem is that the people already there are there for a reason. Murderers and Rapists would be there waiting for you. Another is getting in. Prisons are just as hard to break in as to break out.

In a walking dead style apocalypse, would prisons be the safe havens they are painted as? What would get in the way of this?