Sitting on the clock tower in Piazza dei Signori, the astronomical clock of Padua was built in 1344 and is one of the oldest clocks in the world still in working order. The designer, Jacopo de’Dondi, became so famous for this work that his family name was later changed to “Dondi dell’Orologio,” or “Dondi of the Clock.”

The magnificent timepiece has a 24-hour dial, so the hour hand makes a full rotation only once a day, not twice, moving at half the usual speed and starting at the right (“zero hour”) rather than at the top. The clock also strikes the hours on a bell from 1 to 24. The dial shows the day of the month, the current phase of the Moon, the motion of the planets, and the position of the Sun in the Zodiac.