Semproniano stands on top of the hillocks which separate the valleys of the Albegna and Fiora rivers. During the Middle Ages it belonged to the Aldobrandeschi: in 1331 it was besieged by Sienese troops commanded by Guido Hiccio da Fogliano, but Siena only hecame sole owner in 1424. The center still maintains its medieval flavor, with narrow alleys and stone homes which wind up towards the ruins of the Aldobrandeschi fortress where only the foundations of a powerful tower still remain. The church of Santa Croce (XII century) rises next to the fortress and still holds a wooden crucifix of the XII century. Lower down, there is the pieve with bell tower with two sets of windows with one opening, dedicated to saints Vincent and Anastasio; built by the Aldobrandeschi (XIII century) it has Roman-Gothic windows, travertine ashlars and walls built in rows. On the lunetta of the travertine facade, between the patron saints, there is an Aldobrandeschi lion. Inside, a painting of the Rosario attributed to Francesco Vanni. In the new part of town, outside the ancient walls, one encounters the oratory of San Rocco, characterized by a renaissance arch: it was built around 1476 as au offering against the plague epidemic. At the entrance of the road leading to Fibbianello there is the church of the Madonna delle Grazie founded during the sixteenth century: inside, a fresco representing Sant'Antonio da Padova by Francesco Nasini.