HM Prison Full Sutton is a Category A and B men's prison in the village of Full Sutton, near Pocklington in the East Riding of Yorkshire, England. Full Sutton is operated by Her Majesty's Prison Service and holds some 600 inmates. The prison's primary function is to hold, in conditions of high security, some of the most difficult and dangerous criminals in the country.The Prison also has a unit known as the 'Close Supervision Centre' which is referred to as a "Prison inside a Prison".