An Italian art researcher who has sunk years into unraveling the mysteries of the Mona Lisa claims to have identified the bridge painted in the portrait’s backdrop, according to The Guardian. The historian, Silvano Vincenti, told reporters at Rome’s foreign press association that the bridge was the Romito di Laterina, which stretched across the Arno river in the Tuscan province of Arezzo. “The distinctive form of the Arno along that stretch of territory corresponds to what Leonardo portrayed in the landscape to the left of the noblewoman depicted in the famous painting,” Vincenti said. The key clue, he added, lay in comparing the number of arches of the Romito (only one of which remains today) and the bridge in the painting. Vincenti also combed through a trove of historical documents and modern-day drone images to reach his conclusion. Vincenti has floated several controversial theories about the Mona Lisa’s origins since 2010, including that the portrait’s subject has a secret code painted in her eyes. He also claimed to have unearthed the painter Caravaggio’s skeleton in a coastal Tuscan town, an assertion that other historians have disputed.