Nine metres below the Trevi Fountain there is a Roman apartment block, a water reservoir that once supplied a whole district of the ancient city, and the remains of a fourth-century aristocratic house. It was excavated between 1999 and 2001 and is open to visitors as the Vicus Caprarius — the "City of Water". Someone hid more than 800 bronze coins in a wall cavity down there. They were still in the wall when the archaeologists reached it, roughly fifteen hundred years later.
Almost nobody standing in the crowd above knows any of this is there. The site is a few minutes' walk from the fountain basin, and on most days it is nearly empty while ten to twelve thousand people photograph the marble overhead.
The Vicus Caprarius: what was actually found
The excavation began as building work on a derelict cinema and turned into one of the more remarkable urban digs in modern Rome. Three distinct things came out of it.
The first is an insula — a Roman apartment block. Brick-stamps found in place date its reconstruction to the years after the great fire of 64 CE, which puts real evidence behind the dating rather than an inference from style.
The second is a castellum aquae, a water-distribution reservoir, added around 150 CE. This is the piece that gives the site its name. Water arriving from outside the city was collected here and split between the surrounding streets and buildings.
The third is a domus from the fourth century, an aristocratic house fitted with polychrome marble and mosaic floors — the insula having been converted upward in status at some point in its long life.
The coin hoard
More than 800 bronze coins were found concealed in a wall cavity.
The most likely explanation is that somebody hid them during the Vandal sack of Rome in 455 CE and never came back for them. That reading fits the dates and it fits the circumstances.
Worth being precise about the difference. The hoard is documented, and so is its date range. The motive — someone hiding their money from the Vandals — is the strongest available inference, not something anyone wrote down at the time. It is the kind of detail that gets repeated as established fact, and it isn't one.
Water that has never stopped running
The fountain is fed by the Aqua Virgo, an aqueduct completed in 19 BCE under Agrippa. The same spring has supplied this spot continuously for more than two thousand years.
That continuity is not a figure of speech. In 537 CE, during the Gothic siege, Vitiges cut the aqueducts supplying Rome. The Aqua Virgo was the only one that kept flowing — largely because much of its length runs underground and was harder to reach. Water from those same springs, about 13 km outside the city, comes out of the fountain today.
If you want the strangest version of that fact: water discharging from the Trevi flows down into the excavated Roman cisterns at the Vicus Caprarius, where you can watch Aqua Virgo water moving through second-century masonry.
The myth, checked
The best-known story about the Aqua Virgo is that it takes its name from a young girl who showed thirsty Roman soldiers where to find the spring.
It is a good story and it is probably just a story. Agrippa's construction in 19 BCE is solidly documented. The maiden is an origin myth — the sort of tale that attaches itself to a water source to explain why the water is so pure. We say so rather than repeating it, because a guide that rounds up its uncertainties isn't worth listening to.
Why it's called Trevi
From tre vie — three roads. A junction, long before it was a spectacle.
There was a fountain here well before the one you see. In 1453, Leon Battista Alberti built a plain basin at the terminus of the aqueduct for Pope Nicholas V. Functional, unremarkable, and the direct ancestor of the thing that now stops traffic.
The competition that got cancelled
In 1730, Clement XII held a competition for a proper fountain. Alessandro Galilei won it.
Galilei was Florentine. The Roman guilds objected, loudly, to a Florentine taking a Roman commission, and the award was revoked. In 1732 the work went instead to Nicola Salvi, a Roman.
Salvi spent the rest of his life on it. He ruined his health inspecting the cold, damp aqueduct vaults beneath the site and died in 1751, eleven years before the fountain was finished. Giuseppe Pannini completed it, and it was inaugurated on 22 May 1762 — thirty years and three popes after Salvi was appointed.
One detail from that construction survives in plain sight. Salvi carved a large, entirely non-functional travertine urn into the balustrade, known locally as the Asso di Coppe — the ace of cups. The story attached to it is that a local barber kept criticising the design, and Salvi put the urn exactly where it would block his view.
Four things people get wrong
| Claim | Verdict | What is actually the case |
|---|---|---|
| The central figure is Neptune | False | It is Oceanus, the Titan of fresh water, flanked by Tritons |
| The water is pumped from the Tiber | False | It comes from the Acqua Vergine springs, around 13 km outside Rome |
| The coins are collected by private contractors | False | They go to the Catholic charity Caritas, funding food banks and social programmes in Rome |
| It was built in a few years under one pope | False | Thirty years, three popes and two lead architects |
The coins today
Roughly €3,000 a day is lifted out of the basin. All of it goes to Caritas.
And if you were considering getting into the water for the photograph: entering the fountain or climbing on the marble carries an administrative fine of €450, enforced around the clock.
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Written from Wanderlight's research dossier for Trevi Fountain — the same one the narration is written from. Where the evidence is thin, this page says so rather than rounding the uncertainty up.