The awe-inspiring new back door, made of solid oak and sporting two locks, looked equally impregnable.

The name "maiden" probably means a "fortification that looks impregnable" or one that has never been taken in battle.

It was a huge fortress, which looked absolutely impregnable; nor in ten years had Falsa been able to reduce it.

A doughty building made of rosy bricks, it looks impregnable and was: although gutted by the earthquake, the exterior stayed put.

The rusted iron gates before them looked impregnable, like the forest itself.

Set in an almost perpendicular rock, it looked impregnable.

The security at Rockefeller Center may look impregnable, but it's a piece of cake for a lowly telephone company technician with a laptop and scanner.

Teams can fight back from seemingly impossible positions or collapse when looking impregnable.

At the moment he looks pretty impregnable and he feels like he is going to save everything.

The front door looked impregnable, but a side window was open.