Located to the right of the St Mark’s Basilica and overlooking the lagoon, the Clock tower was once the entrance door to the Mercerie, an area for all types of trading that led up to Rialto, the banking center Serenissima.
The Tower, about thirty meters high, was built between 1496 and 1499 to a designs of Mauro Codussi and initially was only composed of the central body - the tower. In addition to the numerous adaptations that occurred over the years was the addition of the side wings and, towards the mid-18th century, some upper balustrades by the architect Giorgio Massari, giving the tower its present appearance.
Two large bronze statues were laid on the roof of the tower, known as the Moors by the Venetians due to the dark color of their skin, which reminded them of the black slaves present in the city. The two statues, melded by Ambrogio Delle Ancore, are 270 cm high and are moved by a mechanism which allows them to rotate and beat the large bronze bell placed between them with a hammer, marking the hours.
The two Moors are different from each other: one has a beard, and is called the old, the other is without a beard is called the young. They both beat the hour with their hammer differently: the old beats the hours two minutes early, the young beats exactly on time. It is said that the old represents time past, while the young represent the future.
On the façade, immediately above the portico, is a large astronomical clock face, 4.5 meters in diameter, that marks the 24 hours, the position of Saturn, Jupiter, Mars, Venus and Mercury, the phases of the moon and the position of the Sun in the Zodiac. The same clock face is even on the other side, the side of the Mercerie, but it is simpler, only marking the hours. Unveiled with the Tower in 1499, the clock is a technical marvel of the inventiveness of the brothers Gian Paolo and Gian Carlo Rainier from Reggio Emilia.
Above the clock dial is a niche with a statue of the Madonna, where two small windows on the sides show the hours and minutes in Roman numerals, which change every five minutes.
During the day of the Epiphany and in the week of the Ascension the two small windows are closed and become little doors. Every hour an animated procession winds through the small doors, composed of wooden statues of the Magi who, preceded by an Angel, pass in front of the Madonna and bow before her.
There was no need to intervene with the mechanisms of the clock for nearly two centuries, but then the machine was then often repaired. The most recent restoration, carried out between 1996-2006 by the City of Venice with the participation of Swiss company Piaget, gave this beautiful machine back to the city and history.