Located in the belfry to the left of the church, this astronomical clock was made in Strasbourg in 1933.
Each level moves differently. Thus at the lower level, a chariot with two horses driven by a divine figure indicates the days of the week, whilst at the second level, Death moves its scythe as a premonitory sign in front of a child, a young man, a soldier and an old man, representing the four stages of life. Further up, there are scenes from the Nativity, the Epiphany, the Resurrection and Pentecost.
The local legend is no afterthought, as it is represented in the uppermost section. It is the Madonna della Lettera, the Patron Saint of Messina, handing a letter of thanks to the city's ambassadors for granting their protection to its inhabitants, converted to Christianity by Saint Paul the Apostle. The two people striking the bell are also from local tradition, as they are identified as Dina and Clarenza, two young girls who lived during the time of the resistance against the people of Anjou.
At midday, all of these figures begin to move, whilst a lion, the symbol of the city's vitality, roars three times and the cock begins to sing.