The church of San Leonardo in Montefollonico has been documented since 1216. Characterised by a transitional style between Romanesque and Gothic, it has a single nave with a transept limited to the left arm. The façade is crowned by a cornice supported by hanging arches resting on corbels decorated with motifs that are repeated on the right side. There is a beautiful, strongly splayed portal with small columns with richly decorated capitals and a round arch. The lintel is supported by carved corbels. The brick oculus appears to be the result of a later renovation. On the right side, there is another portal, with jambs flanked by small columns with foliage capitals, and two Gothic single-lancet windows. The building is characterised by its carefully crafted stone wall facing.