Though the island is only 37 acres, its ruins reflect the Mediterranean’s rich history, a tumultuous succession of invasions and settlements.

There are stone basins dating to ancient Roman times that were likely used for the preparation of garum, the fermented fish sauce ubiquitous in the era’s cuisine.

There is a medieval well, and the watchtower is believed to be part of Sicily’s defensive system of coastal fortifications against pirates and Ottoman invaders that was revamped by the Florentine architect Camillo Camilliani in the 16th century.

One of the countess’s ancestors, Rosolino Pilo, who died in 1860 during Garibaldi’s Expedition of the Thousand, a campaign that led to the creation of the Kingdom of Italy, used to go to the island, “because it was isolated, and he could think and read,” she said.

When they were young, the countess and her siblings were habitués of the island, taking fishing boats from the town of Isola delle Femmine across the strait that separates it from Sicily to sunbathe, swim and go snorkeling. (A bit of sports trivia: Joe DiMaggio’s fisherman father hailed from the town.)

“The water is uncontaminated, and rich with coral and fish,” said the countess, who is an artist and often depicts fish and underwater scenes in her art.