Stone canon balls, used with the bombard-type of canon that is exhibited inside the museum. 15th/16th century.

The bombard is a cannon or mortar used in medieval times. It was a large caliber, muzzle-loading artillery piece mainly used during sieges to throw stone balls at opponent’s walls. The primary use was to break down the walls of the enemy so the army could get to the enemy.

Correspondent: J.M.Criel, Antwerpen
Source: Wikipedia.