The hills around Rome are threaded with farm tracks and old mule paths, and most of them lead somewhere worth arriving at — a waterfall in a wood behind Cerveteri, a village on a rock in the Monti Ruffi, an empty ridge above the Bracciano crater.
You cannot take a rental car down any of them, which is exactly why these days exist. A guided quad ride is two to four hours of dust, noise and hillside, usually finishing somewhere with food.
No experience is needed for most of them: quads are automatic and the guide sets the pace. Bring clothes you do not mind ruining, because you will.
The two areas that do most of this are the hills behind Cerveteri, north-west, where the tracks run through Etruscan farmland to a waterfall in a wood, and the Monti Ruffi and Monte Flavio, east, which is steeper and rougher and where the long days are. Sunset runs are a thing in both: three hours, and pizza in a village square afterwards.
A quad is automatic and easier to ride than a bicycle, which is why the operators can take complete beginners out in convoy. What varies between them is not the machine but what they let you do on it: some rides are a gentle loop, some are five hours of hard off-road, and one goes two hours on the quad and two on foot to reach a crashed aircraft still lying on the mountain. The card carries the operator's own description of which.
The rule that catches people out is licences and passengers. It changes from operator to operator and from vehicle to vehicle, and it is the one thing not to leave to the morning. Where they publish it, it is on the card; otherwise the phone number is, and a two-minute call settles it.