In the district of the Trastevere is piazza Santa Maria in Trastevere, call thus for being where it is the church Santa Maria in Trastevere, oldest of the city.

According to the legend, the church of Santa Maria in Trastevere was constructed on an oil fountain that brought the day that Jesus was born. It probably was the first official cult place of to the Christianity.

The interior of this XIIth century church, constructed over a VIIth century one, is impressive with spectacular mosaics of Cavallini (XIth century). It is one of the best of the city.