Pavia once had an upside-down tower, the “Torre del Pizzo in giù.” According to legend, Andreotto del Maino, head of the del Maino family in the 15th century, was so fed up with his son Giasone’s unpromising academic career that he vowed to build an inverted tower if only he graduated. Giasone not only took his degree but became one of the most esteemed jurists of his age, so Andreotto fulfilled his promise.
The tower was demolished in the 18th century, “destroyed through stupid timidity,” writes the Irish historian Kenelm Henry Digby, “when it was too late discovered that it had been built with such skill that it might have stood for many ages.”
(Thanks, Daniele.)