Iberian site of El Castellàs Nature · Sierra Engarcerán, La Plana Alta, Castellón Image of Sierra Engarcerán, not of the place itself. The remains of an Iberian settlement in the municipal district of Sierra Engarcerán, in an area with nearby Levantine rock paintings declared World Heritage by UNESCO. Photo: Juan Emilio Prades Bel (CC BY-SA 4.0) What to see and do in Sierra Engarcerán