This is high Maestrat country, where Castellón's mountains roll into Teruel's, and the small rock shelter called the Covatina del Tossalet del Mas de la Rambla belongs to a family of sites that UNESCO lists together as the Rock Art of the Mediterranean Basin on the Iberian Peninsula. Under overhangs like this one, hunters and early farmers painted small, lively figures in red and black: archers in mid-stride, deer and ibex, scenes of hunting and gathering. The style, called Levantine art, is unusual for its movement and its storytelling, and many of the shelters are tiny, fragile and kept behind fences. Access is often by guided visit only, so check with the local tourist office before you count on seeing the paintings.
The nearest town is Vilafranca, also written Villafranca del Cid, a stone village of about two and a half thousand people at more than a thousand metres. The surrounding hills are wrapped in an incredible web of dry-stone walls, huts and terraces built by generations of farmers and shepherds, and dry-stone building is a craft the town is proud of. Just across the border into Aragón, La Iglesuela del Cid is a beautiful little place with arcaded streets and noble houses, and Cantavieja, perched on a cliff, is a short ride further.
The riding is the real reason to be here. Roads in the Maestrazgo are almost empty, mostly well surfaced, and twist across high plateaus and through gorges with corner after corner; in places you can ride for half an hour without meeting a car. Be aware of the conditions: winters are cold and can bring snow and ice, summer afternoons get thundery, and there is gravel on some bends and livestock on the road. Spring, with green fields and wildflowers, and early autumn are the best seasons.
Fuel is the thing to plan. Small towns here may have a single pump or none, and opening times can be limited; the larger services are in Morella and further toward the coast. Fill up when you can and do not run the tank low. Vilafranca has bars and a few restaurants where you can eat honest mountain food: cured ham, local lamb, hearty stews and the cheese and truffles the area is known for in season.