guardhouse

guardhouse
    n 1: a military facility that serves as the headquarters for
         military police and in which military prisoners can be
         detained
    

Guardhouse \Guard"house`\, n. (Mil.)
   A building which is occupied by the guard, and in which
   soldiers are confined for misconduct; hence, a lock-up.
   [1913 Webster]
    

45 Moby Thesaurus words for "guardhouse":
      POW camp, bastille, black hole, borstal, borstal institution,
      bridewell, brig, cell, concentration camp, condemned cell,
      death cell, death house, death row, detention camp, federal prison,
      forced-labor camp, gaol, house of correction, house of detention,
      industrial school, internment camp, jail, jailhouse, keep,
      labor camp, lockup, maximum-security prison,
      minimum-security prison, oubliette, pen, penal colony,
      penal institution, penal settlement, penitentiary, prison,
      prison camp, prisonhouse, reform school, reformatory,
      sponging house, state prison, stockade, the hole, tollbooth,
      training school