Conservationists in Rome are worried that a concert by the Rolling Stones in the city's Circus Maximus could pose a threat to the fragile ruins of the ancient chariot racing stadium.
The British rockers, who played in Macau earlier this month, are set to perform for 65,000 fans on June 22.
The influx of spectators has raised concerns among heritage officials, who warned of "unpredictable consequences" and possible "acts of vandalism" in a "very fragile" area.
The office of archaeological supervisors said: "The choice of the Circus Maximus for the Rolling Stones concert brings a measure of risk for the heritage of the area that is not only heightened but also hard to predict."
It called for an "extraordinary security plan" to be put in place to protect historical sites.
But it is not just the Rolling Stones who are bringing huge crowds to the city.
The canonisation of two former popes - Jean Paul II and Jean XXIII - on April 27 is expected to bring as many as two or three million people to Rome.
None of this has Mayor Ignazio Marino - himself a Rolling Stones fan - too concerned.
In a letter published on Sunday in the daily Repubblica, the leftist mayor said the chance to hear "the passionate chords of their rock in the archaeological heart of the city will be yet another demonstration of 'the great beauty' of Rome".
His mention of the "the great beauty" - or " la grande bellezza" - bore reminders of the recent Paolo Sorrentino film of the same name, which won the Academy Award for best foreign language picture earlier this month.
The government hopes the Rolling Stones concert can turn into a full weekend of cultural events that will help rejuvenate the staid reputation of the city, while also providing a much-needed economic boost.
Rome's chamber of commerce predicts that the canonisations and the Stones concert could see the influx of tourists rise to 40 million this year, up from 35 million last year.