From here head downhill for a couple of kilometers and then again follow the comfortable up and down pattern of the road. At 17km you will reach the plain, which skirts the Ombrone valley’s mountains on the right. Soon after you come to the hamlet of Stiacciole (19.7) where, near a T-crossing, you turn left and take the S.P. 159 in the direction of Scansano. After 300 m turn left again to enter the medieval village of Istia d'Ombrone (21).
Passing through the village to get back on the S.P. 159 "Scansanese", turn left and go over the bridge (22) that crosses the Ombrone River. After about 2.5 km you will see a service station with a snack bar. Immediately after the bar (24,8) you leave the “Scansanese” road, by turning left onto the S.P. 17 "Voltina" in the direction of Arcille. Crossing the bridge over the Trasubbie stream (27.6) continue on towards nearby Arcille (28.8) where you will enter a traffic circle and turn left in the direction of Campagnatico and Cinigiano, keeping to the S.P. 17 and passing the hamlet of Sant'Antonio (32).
Following the S.P. 17, stay straight moving as quickly and safely as you can; the road isn’t very wide, though there isn’t much traffic, it’s advisable to keep prudently to the right and be aware of speeding cars. After Sant'Antonio continue for a further 1.5 km until you reach a fork (33.5): here turn left onto the S.P. 18 toward Campagnatico. In a little less than 3 km you will arrive at a vantage point onto the Ombrone plain overlooking the bridge over the river (37.5). The last segment of the route climbs towards Campagnatico: you will ascend for a final 4.4 km until you reach the fork on the right which leads towards the town (42.3).