Our watercolour shows the ‘two twin churches’, as they are called Santa Maria in Montesanto (1675) and Santa Maria dei Miracoli (1678).

The churches were built at the behest of Alexander VII, but the works ended only after the death of the pope (1667), profoundly renewing the appearance of the square, and constituting the two poles of the Roman Trident, formed by Via del Corso, Via del Babuino and Via di Ripetta.

Apparently identical, the twin churches of Santa Maria in Montesanto and Santa Maria dei Miracoli had as their main task that of organizing the northern access to Rome.

The work was entrusted to the architect Carlo Rainaldi in the 17th century on the orders of Pope Alexander VII. The two churches were originally supposed to be symmetrical, but the architect Rainaldi had to deal with the fact that the available space on the left was less than that on the right. The problem was solved by equipping Santa Maria dei Miracoli with an octagonal dome and Santa Maria in Montesano with a dodecagonal one, a shape that allowed it to be squeezed into the little space available. For the same reason, the plan of the church on the left is elliptical, while that of the other is circular; despite this, the two buildings, due to a particular optical effect, appear perfectly identical when seen from the center of the square.  

For both churches, the model is the Pantheon. The bell towers are from the eighteenth century and also in this case different from each other.

 The church of Santa Maria in Montesanto owes its name to the fact that it was built on the site of a small place of worship belonging to the Carmelites of the province of Monte Santo in Sicily, however, almost everyone knows it as the "church of artists". As for the church of Santa Maria dei Miracoli, according to tradition, it is said that in 1325 a woman, to save her son who had fallen into the Tiber, invoked an image of the Virgin painted on the walls along the river. The miracle occurred and, as a thank you, a chapel dedicated to Mary was built, the original effigy of the Madonna dei Miracoli was transferred for safety to the new church in Piazza del Popolo, which was renamed Santa Maria dei Miracoli.