Leave the highway A1 at Firenze Certosa and take the Firenze-Siena towards Siena.
From Florence (150 Km)
Take the freeway Florence-Siena (direction Siena). Take the exit for SS 223 Siena-Grosseto. Continue in SS 223 Siena-Grosseto (direction Grosseto). Take the exit marked Paganico. Follow the signs Monte Amiata.
Or, alternatively, from Siena (80 Km)
Take SS 2 Cassia (towards Rome). Take the exit marked Abbadia San Salvatore. Follow the signs Monte Amiata.