Among the earliest documented fountains in the city’s history, it was fed by springs located nearby.
As early as Roman times, it was known as fons opacinus, a spring of tramontana, because of its location that turned to the north.
Apparently, the spring enjoyed great fame for its healing qualities and many outsiders came to admire it.
According to descriptions by Moses of Brolo in Liber Pergaminus (1120-1180), its vaults, floor and walls were covered with marble.
Both inhabitants and horses could draw from the fountain; it had a wash-house and a very large cistern.