Lari is a walled mountaintop frazione, or hamlet, in the comune of Casciana Terme Lari, 60 km southwest of Florence and 25 km southeast of Pisa, in the Tuscany region of Italy. The municipal seat of its comune, Lari dates from at least the 9th century BC, a fact established by its traces of Etruscan architecture. It sits at a high elevation for Tuscany and centers around a castle, with distant views in all directions. Physician Eusebio Valli was born in the hamlet.