 From its round form is derived the usual colloquial designation in Vienna, "Gugelhupf", meaning a round Austrian cake.The notion that the Fool's Tower is a conversion of the idea of the Panopticon of Jeremy Bentham does not apply, since the cells are not controllable from a central observation post.Already at the oldest model, the Fool's Tower has at the roofridge a lightning rod or a Blitzfänger.