Antennas attached to existing buildings or structures,
belfries, chimneys or smoke stacks, church spires, communication towers,
conveyors, cooling towers, cupolas, fire or parapet walls, flagpoles,
grain elevators, masts, ornamental towers and spires, public monuments,
silos, smokestacks, steeples, water towers and windmills, water tanks
or other roof superstructures.