A belfry is a structure in which bells are hung, often associated with churches and religious sites. Early examples were often free-standing, away from the church building, but since the 11th century more usually took the form of a bell tower incorporated into the main church structure. The openings to allow the sound to escape are usually louvred, to protect the bells from the weather. The term belfry is also sometimes used to describe the framework supporting the bells.
A belfry was originally a movable wooden siege tower used in the Middle Ages by armies besieging a fortification, known as a berfrei in Old French.