* Literal: The ancient fortress stood atop the hill, its walls weathered by centuries of wind and rain.
* Figurative: Her determination was a fortress, unyielding against the tide of negativity.
* Metaphorical: The city was a fortress of concrete and steel, isolating itself from the surrounding countryside.
* Descriptive: The castle, with its towering walls and deep moat, was an imposing fortress.
* Historical: The Roman legions built a fortress to protect the northern border of the empire.