Montegiovi Castle stands on a hillock of sandstone rock a few kilometres from Castel del Piano. The castle was first mentioned in 1209 in a document drawn up by Emperor Otto IV which confirmed the ownership of one half of the castle by the bishop of Chiusi and the other half by the abbeys of Sant’Antimo and San Salvatore. Having undergone a troubled period when it was taken over by Siena (changing hands between the important city families of the Tolomei, the Buonsignori and the Salimbeni), the castle was placed under the direct control of the Republic in the 15th century. Traces of the ancient walls that enclosed the village, which follow the morphological trend of the hill on which Montegiovi stands, are still visible today. The best preserved sections of walls are located near Sant'Elena Gate, the entranceway to the village, its round arch resting on two protruding corbels. In this setion, the walls incorporate the external wall and the bell tower of the chapel dedicated to Saint Helena and Saint Roch. On the south-western side, the keep which has a polygonal plan and has been incorporated by the surrounding houses, is still visible.