Siena to Piombino
Buongiorno,
If you have a car, then I would take the route that goes through Sovicille, Chiusdino, towards Follonica and then Piombino. (these little towns especially Sovicille are adorable!)
If you need to use public transport...you need to catch a bus to Grosetto then a train to
Campiglia Marittima then another bus to Piombino. It is a bit complicated but time wise it only adds about an hour and a half to your schedule...which is not bad - believe me!
Buon Viaggio,
Donna Denise