We need more information from you. A prison is a place and not a "who" and a fortress can also be a prison.
Fortress prison
Sinop Fortress Prison was created in 1887.
An alcaide is a governor or commander of a Spanish or Portuguese fortress or prison.
Landsberg Am Lech Fortress Prison.
An Armory and formerly as a fortress.
It was a Royal fortress and prison.
An alcayde is a governor or commander of a Spanish or Portuguese fortress or prison.
a heavy protected area and inpenetrable building
the tower of London is a the majesties royal palace and fortress. the tower was used as a royal palace, prison and fortress.
The prison was the fortress of La Bastille, which was stormed on the 14th of July, 1789.
Bastille was a fortress in Paris, France used a state prison, and in resolving of internal conflicts in France. The Bastille was a fortress in Paris used by the kings of France as a state prison.
A place of defense; a fortress; a garrison; a fortress; a garrison or guardhouse.