The Val d'Orcia is the Tuscany of your dreams — and it has almost no public transport. Those rolling hills, lone cypress trees, medieval hilltop towns? Spread across 60km of countryside with bus service twice a day if lucky.
Firenze–Siena superstrada (free) to Siena, then SS2 (Via Cassia) south. Passes through Buonconvento, Montalcino, San Quirico, Pienza, Montepulciano — each 15–20 min apart. The SS2 is one of Italy's most beautiful roads.
Full-day tours hitting Montalcino (Brunello), Pienza (pecorino), Montepulciano (Vino Nobile). Usually includes lunch at an agriturismo.
Montalcino (Brunello wine) → Sant'Antimo Abbey (Romanesque perfection) → San Quirico d'Orcia → Pienza (the "ideal city") → Montepulciano (Vino Nobile). 60km loop, full day.
Rent a car in Florence and drive. No Plan B works for a day trip. If you refuse to drive, book a guided tour — it's one of the best days you can have in Italy.