the bridge that has been seen by more people than any other (very likely true) but until today, was not identified or known - has finally been identified, and located. The bridge in the background of the Mona Lisa painting

Research coordinated by the historian Silvano Vinceti has identified the bridge that Leonardo da Vinci depicted in the background of the Mona Lisa, as the Romito bridge in Laterina, in the province of Arezzo. 

Based on historical documents and comparisons between current photographs and the painting, it was possible to identify the real Mona Lisa bridge. 

"It is the Romito Etruscan-Roman bridge, also known as Ponte di Valle, located in the municipality of Laterina in the province of Arezzo," explained Vinceti. 

 The Romito bridge had four arches, resting on two cliffs, was part of a byway, or shortcut, that made it possible to shorten the journey between Arezzo, Fiesole and Florence by several kilometers.

"Only one arch remains of the bridge today, but in the period between 1501 and 1503 the bridge was functioning and it was very busy, as shown by a document on the state of assets on Medici family properties, found in the State archives of Florence". 

It was precisely at that time that Leonardo was in the Val d'Arno area, first at the service of Cesare Borgia, and then for the gonfalonier of the Republic of Florence, Pier Soderini.

https://www.ansa.it/sito/notizie/cultura/arte/2023/05/03/e-il-ponte-romito-di-laterina-in-provincia-di-arezzo-quello-che-leonardo-dipinse-nel-paesaggio-della-gioconda_9726cf0a-fbbc-4329-8bc6-abb23fcd1f5b.html

https://upload.wikimedia.org/wikipedia/commons/e/ec/Mona_Lisa%2C_by_Leonardo_da_Vinci%2C_from_C2RMF_retouched.jpg