The impregnable fortress was to become his prison for the rest of his life.

Can he build an environment and culture to bring the whole group together through leadership, managing up and down and creating an impregnable fortress in the group?

This attack was one of the first occasions on which artillery was used, and breaches were soon made in an otherwise impregnable fortress.

For centuries after its construction in the 10th or 11th century it remained an impregnable fortress.

They requested that they be blessed with impregnable fortresses, which would be everlasting.

Or do you dream of living in a medieval fortress, but still want all mod cons?

You're seated eating lamb and drinking rosé on the restaurant terrace of this lovely medieval fortress.

Pedestrian squares are ringed by blocks of flats which he likened to the walls of a medieval fortress, acting as a barrier between the worlds.

Near the town are the ruins of a medieval fortress.

The medieval fortress was destroyed in the 18th and 19th centuries and reconstructed as a house.

It's a mountain fortress that looks like a monastery, part youth hostel, part luxury eco-lodge.

He thus planned to eliminate humanity by freezing the planet while he and his henchmen remained safe in his remote mountain fortress.

Its destruction forced the claimants from both sides of the conflict to rule from mountain fortresses.

Mountain fortresses were also often constructed as places of refuge during war.