At the end of the Middle Ages, in the woods above Cardoso, there was a village called Casamenta, destroyed according to tradition by Castruccio Castracani, lord of Lucca. According to the oral testimonies of the community, the current sanctuary of San Leonardo was built in the place where the church of that ancient town once stood.
On July 16, 1968, the feast of the Madonna del Carmine, the now rarely visited Sanctuary hosted the wedding of two local young people, Adelmo Santarelli and Bazzichi Maria Adelia.
A plaque inserted in the masonry of the church reports the news that the company of the Santissimo di Cardoso in 1970 restored the sanctuary in memory of its fallen in war.
