1.   Agnes leaned against the castle wall, which was streaming with water, and fought for breath.

2.   One of the earliest explosive devices was the petard, which was a mine used to breach castle walls or gates.

3.   The army was encamped beneath the castle walls.

4.   The castle walls surround the medieval town, which is still inhabited as it has been for hundreds of years.

5.   The majestic castle walls, with their varying bands of stone, were modelled on the walls of Constantinople.

6.   The seagulls bored on the castle wall.

7.   Torches were already flaring on the castle walls when the first wagons carrying the dismantled mangonels rumbled across the drawbridge.

8.   The castle walls were slowly crumbling away.

9.   The army breached the castle wall.