Carla Glori said a three-arched bridge that appears over the left shoulder of the woman with the enigmatic smile is a reference to Bobbio, a village south of Piacenza, in northern Italy, according to the Daily Telegraph.
Glori's theory is based on the recent discovery by another art historian, Silvano Vinceti, of the numbers 7 and 2 concealed in the span of the stone bridge. She believes the numerals are a reference to 1472, the year in which a devastating flood destroyed Bobbio's bridge.
Historical records show that the bridge, known as the Ponte Gobbo or Ponte Vecchio (the Old Bridge), was swept away when the Trebbia river burst its banks that year.
“Leonardo added the number 72 beneath the bridge to record the devastating flood of the river Trebbia and to allow it to be identified,” said Glori, who sets out the theory in a new book, “The Leonardo Enigma.”
Leonardo was born in the town of Vinci in Tuscany but traveled across Italy during his lifetime and worked in Venice, Rome and Bologna.
The artist started painting the “Mona Lisa” in 1503 or 1504 in Florence, but did not finish it until years later, after he had moved to France to work under the patronage of King Francois I.
Most art historians believe the background, which features valleys and mountains, is an idealized landscape drawn from the artist's imagination.
The painting was kept in the Palace of Versailles until it was moved to the Louvre Museum in Paris, and remains the property of the French state. It is believed to be a portrait of Lisa Gherardini, the wife of a wealthy Florentine silk merchant.
