Due to its strategic hilltop position guarding the Val'd'Orcia valley, Montenero was fortified around the year 1000, probably by the Aldobrandeschi as a defence from Saracen raids. Built in 1410, the ancient Lion Gate (Porta Leone) or Medici Gate (Porta Medici) leads to the small historic centre of the town. Erected in 1591 in the centre of a picturesque, well-kept "Piazzetta" (little square) adjacent to the parish Church, the Cisterna di Poggio Valente is decorated with the coats of arms of the Medici and Montenero.
