Two American women allegedly carved their names on the Colosseum, an ancient historical building in Rome, to pose for a selfie.
They were arrested for the act on March 7, news site Buzzfeed reported.
The pair, aged 21 and 25, from California, were reported to security by other tourists. The women are believed to have commited the offence of "aggravated damage on a building of historical and artistic interest".
They allegedly left their tour group and used a coin to engrave the letters J and N about 8cm high onto the walls of the World Heritage site, Buzzfeed reported, quoting Italian news site La Stampa.
The women reportedly said: "We apologise for what we did. We regret it, but we did not imagine it was something so serious."
According to Rome's official website, the Colosseum originally known as the Flavian Amphitheatre, was commissioned in 72 A.D. and completed in 80 A.D. An emperor had the structure built to stage "deadly combats of gladiators and wild animal fights for public viewing" to gain popularity. The building is now a popular tourist spot that attracts almost four million visitors every year.