This vast fortress is one of the greatest surviving castles of the medieval western world.

Somewhere in or below that vast fortress Batik and Archer were prisoners.

Though they were still a mile away, the buildings loomed up like a vast fortress.

Some are now easily accessible, such as the Citadel, the vast raised fortress on the eastern edge of the city that was begun in the 12th century.

It is a vast, walled fortress encompassing an entire park, with tall, sturdy towers at every corner.

The machine was a vast fortress, containing no life, set by its long-dead masters to destroy anything that lived.

The whole vast fortress gleamed like some religions' notion of heaven.

The Nightlords possess the ability to manipulate matter for various purposes (their greatest achievements being the creation of their vast fortresses).

It was a strange, dark fortress, more vast than some cities.

The city center lies within the walls of a vast fortress started by the Venetians and reinforced by the Turks.