Two American tourists were arrested and will likely be fined for defacing part of the Colosseum in Rome. The embarrassing incident happened over the weekend and will cost the pair more than their dignity, possibly leading to thousands of dollars in fines.

In a show of ignorance and selfishness, two female American tourists from California, 21 and 25 years old, were arrested in Rome for vandalizing the Colosseum, according to CNN. The pair carved their initials on the ancient Roman monument's wall, J and N, assuming the structure, which has survived for millennia and is a symbol of Western civilization, would be an appropriate place to leave their mark.

Other tourists caught the Americans defacing one of the Colosseum's walls and alerted security that promptly stopped the women. The two had also decided to commemorate their crime and provide evidence of their culpability to police by taking a selfie.

Roman police charged the two women with "aggravated damage" to a building of historical and artistic value and could face an astronomical fine of more than $20,000. This is the amount a Russian tourist paid after he was caught carving his initials into the monument. Police fined him 20,000 euros or roughly $21,685.

Despite the fact signs litter the monument warning tourists in both Italian and English not to vandalize the structure, the women in their defense said, "We did not imagine it was something so serious," according to the New York Post.

However, it is serious, especially to Roman authorities. The spokesperson for the Special Superintendency for the Archaeological Heritage of Rome told the Guardian, while tourists are well behaved at museums and other structures like the Vatican, they forget that propriety when at an ancient ruin.

"There's a difference in perception. Museums are treated like churches, sacred places where there are things of great value. Whereas the Colosseum is an incomplete building which has already been robbed," the spokesperson said.

Millions visit the Colosseum, but Roman police have struggled to keep up with the numbers, having suffered cuts. Security increases, including metal detectors, focus more on the threat of terrorist attacks rather than misbehaving tourist.