Barns, silos or other farm buildings or structures on farms, church spires, belfries, cupolas and domes, monuments, water towers, fire and hose towers, observation towers, transmission towers (subject to the conditions in Subsection (D) of this Section), windmills, chimneys, smokestacks, flagpoles, radio towers, masts and aerials, parapet walls extending not more than four (4) feet above the limiting height of the building;