The Bell Tower is basically a tower-belfry set apart from the main body of the church, traditionally the tower is square, with an upper, open chamber containing bells. This, in turn, is topped by a conical or pyramidal spire, or an onion-shaped dome. Sometimes a smaller, arcade Campanile will be joined to a church. Those Venetian campaniles which have not been destroyed altogether are today the object of constant restoration work because their foundations so frequently subside.