Castle - Wikipedia

FORTRESS - Definition and synonyms of fortress in the English dictionary

A Mighty Fortress Is My God - The Battle Hymn of The Reformation

fortress - photo/picture definition at Photo Dictionary - fortress word and phrase defined by its image in jpg/jpeg in English

Fortification, Military Science & History of Defense Structures

Definition.org - Fortress Hohensalzburg in Austria.

GitHub - userfrosting/fortress: A schema-driven system for elegant whitelisting, transformation and validation of user input on both the client and server sides from a unified set of rules.

Fortress. Words, Fortress, Nouns

Erebuni - World History Encyclopedia

Carahsoft and CodeLock Forge Alliance to Fortify Government Software Development

15 Defining Parts of a Castle - History Lists