The Rock

is a prison, compared to Alcatraz by Gromry Johnson, a former prisoner. It is likely to not actually be a high-security prison, as Gromry Johnson implied in his interview in Creature Sighted, since Johnson was able to make his way outside to relieve himself, and was only given a stern warning.

History
Not much is currently known about. It has to have been running at least since the time that Hatchet was a child.