Fortress
Fortress , noun
[French forteresse, Old French forteresce, fortelesce, Late Latin foralitia, from Latin fortis strong. See Fort, and compare Fortalice.]
A fortified place; a large and permanent fortification, sometimes including a town; a fort; a castle; a stronghold; a place of defense or security.
Fortress , transitive verb
To furnish with a fortress or with fortresses; to guard; to fortify. — Shakespeare