It was built over the ruins of the Circus Agonalis, a long, rectangular stadium build by Domitian to celebrate the Greek athletic games. In the 15th Century, the city market was transfered here giving the square its festive and live atmosphere. In 1647 Pope Innocent X commisioned the construction of a fountain in the centre of the square to the architect Borromini (who many years later built the church of Saint Agnes, in front of the fountain) but the Pope then commissioned it to Gian Lorenzo Bernini, after seeing a small silver model of his project.
The Fountain of the Four Rivers was unveiled in 1651. It is one of the most beautiful and famous monuments of Baroque Rome and represents the four big famous rivers known at the time, the Ganges, the Nile, the Danube and the Rio de la Plata. The presence of the obelisk Agonale on the fountain was specifically asked by the pope.
The statues of white marble represent:
- the Nile, has the peculiarity of having her head veiled because its sources were then unknown (the people, however, used to say it expressed the contempt by Bernini for the nearby church of Saint Agnes, designed by his rival Borromini - these rumors are not true since the church was built after the fountain);
- the Ganges has a long oar that represents the navigability of this river;
- the Danube points the coat of arms of the Papal family to represent the religious authority of the Pope in the world;
- the Rio de la Plata, the coins near the statue symbolize the silvery color of the waters of this river (again, people said that it expressed the fear that Borromini's church might collapse).
According to the inscription commissioned by Innocent X, the monument offers "healthy amenities to those who walk, drink to the thirsty, lure to those who meditate."
The church of S. Agnese in Agony was built in the place where, in the year 304 AD, the young Agnes was martyred. The church has been rebuilt several times, the latest by Borromini, who designed the majestic church that we see today. Inside the church there is the tomb of Innocent X, the Pope who commissioned the projects which gave beauty to the square.
The other two fountains that adorn the Piazza Navona are the Fountain of the Moor and the Fountain of Neptune, both works of Jacopo della Porta.
Pope Innocent X, in 1652, started a tradition that lasted two centuries and made Piazza Navona a place of enjoyment: he ordered to block the closures of the three fountains, leaving the water overflow to flood the central part of the square. The "Lake of Piazza Navona" became a summer tradition during the weekends of August until 1866.
Not far from the square there's the famous statue of Pasquino, the first "talking statue" of Rome. Talking statues provided were a form of anonymous protest or political expression in Rome. Criticisms in the form of poems or witticisms were posted on well-known statues like Pasquino.