The massive amphitheatre, which witnessed savage fights and the gory deaths of unlucky gladiators and wild animals centuries ago, was eerily silent as the first tourists passed through its gates with new health protocols in place.
Officials said they expected only 300 people – a far cry from the thousands of selfie-taking tourists who pack the stadium on a normal day.
Also visibly absent were the modern-day “gladiators” usually parading outside, waving their plastic swords as they vie for tips for photographs.
Workers took advantage of the lack of crowds to patch up mortar, and a solitary cat was seen roaming on the main deck.
The Colosseum's director, Alfonsina Russo, said it had been “surreal” seeing the empty landmark during the three-month closure,, adding: “It's a symbol of Rome and of Italy.”
“But the sense of emptiness highlighted the great beauty of this place and it's fragility,” Russo told AFP.
Last year, an average of 20,000 tourists visited the Colosseum daily on a combined ticket with the Imperial Forum – the site of ancient Rome's government and religious temples – and the Palatine Hill, where the city's elite built their villas, thrown in.
Seventy percent of those tourists came from abroad.
On Wednesday, visitors from within the European Union will once again be allowed to travel to Italy, with no quarantine requirements – though borders remain closed to tourists from further afield.
Pierluigi, a Roman preparing to enter with his wife, said this was his first visit.
“We took advantage of the fact that foreign tourists aren't here yet,” he said. “I'm excited at the idea of seeing it, being inside.”
Another local resident, Luca, said he was surprised by the lack of crowds but conceded: “There's so much else to see in Rome.”
Things were busier at the Vatican Museum on Monday, where hundreds awaited entry to see the Sistine Chapel and other papal treasures.
Italy's tourism sector is vital for the economy, accounting for about 13 percent of revenues. Museums were allowed by law to open on May 18th, but many still remain closed as they await a greater influx of tourists.
Famous sites throughout Italy have reopened in recent days with strict rules in place, including the ruins of Pompeii and Pisa's leaning tower
On Tuesday, Florence's Uffizi Gallery and its Accademia, housing Michaelangelo's David, are set to welcome visitors once again.