The “Circus Agonalis”
In ancient Rome, just as today, the area around Piazza Navona was called the Campus Martius. Meaning 'the Field of Mars', this was originally a green open area where the Roman military would train, exercise, arm themselves before undertaking campaigns, and disband at the end of them, as armed soldiers were forbidden from entering within the city walls.
During the Age of Augustus (31 BC - 14 AD), intense building activity reshaped the Campus Martius, transforming it from an open field into a densely built-up (though particularly lavish) landscape of bath complexes, temples, basilicas, and other public spaces.
Fig. 2. The Campus Martius during the Age of Hadrian (117 - 138 AD)
followed this tradition, offering the public a recreational space in the newly developed city center. Named the Circus Agonalis after the
, the stadium that Domitian dedicated in 85 AD was given as a gift to Rome’s citizens, becoming the first permanent stadium for
in Rome. It was certainly spacious, able to accommodate as many as 30,000 spectators. This was still far fewer than the nearby
which archaeologists believe could hold some 250,000 people. Yet the emperor's offering was still very much welcome, providing entertainment in close vicinity of the nearby local baths. Because of its smaller size, the Circus Agonalis served as an athletic stadium for a variety of games, including
and even mock naval battles. We only hear of one occasion on which the Circus Agonalis hosted gladiatorial contests - in 217 AD while the
was undergoing repairs for fire damage.
From Stadium to Square
During the Middle Ages, many of Rome’s ancient structures became the (literal) building blocks of the new buildings and churches around them. Materials were taken from major structures from the past, including the Colosseum, much of the
, and also the Circus Agonalis.
Fig. 3. Piazza Navona: Past and Present
Because this deconstruction of the circus left a large open area, this land was paved over and turned into a square. In the late fifteenth century, Piazza Navona began to host a variety of events, including food markets, festivals, and horse training. And in order to cool off during the hot Roman summers, Piazza Navona was flooded on certain days during this period.
But the flooding of Piazza Navona ended when the square was repaved in the nineteenth century, raising the level of the street and changing the drainage system of the piazza. Consigning it to history as a remnant of
Hidden Rome.Fig. 4. Piazza Navona in a 19th-century postcard
The Fountains of Piazza Navona
The three fountains in Piazza Navona, Fontana dei Quattro Fiumi, Fontana del Moro, and Fontana del Nettuno, line the square and provide structure to such a large area. Placed in the center of Piazza Navona and topped with an Egyptian obelisk, the Fontana dei Quattro Fiumi (Fountain of the Four Rivers) is the best known of the square’s three fountains. Designed by Bian Lorenzo Bernini in 1651, this fountain represents the four major continents at the time, and their respective rivers. They are the Nile (Africa), Danube (Europe), Ganges (Asia), and Rio de la Plata (America).

The Navona Obelisk embedded into Bernini's Fontana dei Quattro Fiumi Located on the southern end of the square, Fontana del Moro (Fountain of the Moor) was originally sculpted by Giacomo della Porta in 1575. He sculpted the dolphin and the four Tritons that are featured in the fountain, but it was Bernini that sculpted the central statue of the Moor that was added in 1653. The final fountain at the northern end of Piazza Navona is the Fontana del Nettuno (Fountain of Neptune). Surprisingly, the original fountain did not have any statues. The basin of the fountain was designed in 1574 by Giacomo della Porta, and the simple design stayed until the nineteenth century. Antonio della Bitta added the center sculpture of Neptune, while Gregorio Zappalà completed the other sculptures in 1878, resulting in the fountain we see today. →