A family in New Orleans, USA, made an unusual discovery while cleaning their grass-covered backyard. Beneath the grass, they found a mysterious marble slab inscribed with Latin letters including the phrase “Spirits of the Dead.”

Daniela Santoro, an anthropologist at Tulane University, said, “The fact that it was in Latin made us stop, right? I mean, you see something like this and say: (Well, this is not ordinary).”

Feeling curious and concerned, Santoro contacted her colleague in classical archaeology, Susan Losnia, who quickly realized the slab was a 1900-year-old tombstone of a Roman sailor named Sextus Conginius Virus. Losnia said, “When I first saw the picture Daniela sent me, I felt a shiver down my spine because I was shocked.”

Further investigation by Losnia revealed that the slab had been missing from an Italian museum for decades.