In a city of ancient monuments, it's one of the most impressive and most visited.
The Trevi Fountain is the endpoint of an ancient Roman aqueduct that has brought water to Rome for around 400 years. Renovated under Pope Clement XII in the 1700s to make the site more dramatic, it is now one of the world's most famous fountains.
Millions of people visit every year to throw a coin with their right hand over their left shoulder for good luck — an act that is also said to ensure that you'll one day return to Rome.
And in one of the world's tourist capitals, the endless stream of people means an endless stream of coins plopping into the pale blue water and settling at the bottom. Coins are pulled out once a month by city workers as they clean it, totalling over a million euros per year.
Traditionally the money goes to a Catholic charity for the poor and homeless called Caritas.
But in a city with crumbling infrastructure, local government has a new purpose in mind for all those coins.
Mayor Virginia Raggi has proposed that the money now be used on infrastructure projects in the city, a move agreed upon by city councillors. The change is supposed to come into effect in April.
But local headlines accuse the mayor of taking money from the hands of the city's poorest.
"We did not foresee this outcome," said Caritas director Father Benoni Ambarus in an interview with Avvenire, the newspaper of the Italian bishops' conference.
"I still hope it will not be final."
Another story on the controversy that ran in the newspaper was headlined, "Money taken from the poorest".
Trevi Fountain has been featured in multiple films, including "Three Coins in the Fountain" from 1954 and Fellini drama "La Dolce Vita".