By car. From Rome, take the Cassia Bis highway SS2 and exit at Sette Vene. Follow signs for Calcata. Parking is limited and mainly along the side of the road that passes Calcata. In the high season this may involve quite a long walk to get back to the village.
By bus. Hourly Cotral buses (http://www.cotralspa.it) leave from the Saxa Rubra bus station to the north of Rome. The journey time is about 45 minutes although this could be much more on sunny weekends.