Up on the Maestrat plateau in Castellón the country changes its mind about what it is. Below you the Mediterranean orchards give way to bare limestone, juniper, kermes oak and the stone-walled fields of a place that was once rich in sheep and wool. Centelles lies in that landscape between Catí and Albocàsser, and the shelter here is one of a scatter of rock paintings that make the Valencian hills one of Europe's richest outdoor galleries of prehistoric art.
The roads from Catí and Albocàsser wind across open upland between fields and old farmhouses, the surfaces are typically fair, the traffic is close to nothing, and corners come in easy sets that leave plenty of time to look at the Penyagolosa massif standing on the horizon to the west. The hills are cold in winter and sometimes snowy, and the wind can pick up hard across the open ground, so check the forecast. Late spring, when the broom is yellow and the barley is green, is the best moment.
Catí is worth knowing for its goat cheese, an old local speciality that you can buy in the village and eat on a bench with bread, and for the Gothic town hall that speaks of its medieval wealth. Albocàsser lies a few kilometres to the south and is another quiet farm town with a good square. Both are small enough that fuel is not guaranteed, so plan to fill in Alcalà de Xivert, the nearest town of any size, which is twenty-three kilometres away towards the coast, before turning inland.
As for the paintings, the typical pattern in this district is a low shelter along a barranc wall with a few faded red figures, often fenced to protect them. The nearby Valltorta museum at Tírig is the place to understand what you are looking at, and it is better to go there first than to arrive cold at a shelter and be disappointed that the images are smaller than the story.