Castellón de la Plana (kästĕlyōnˈ dā lä pläˈnä) [key], city (1990 pop. 135,863), capital of Castellón de la Plana prov., E Spain, in Valencia, 3 mi (4.8 km) from its Mediterranean port of Grao. It is the center of Spanish orange production and has a large petrochemical industry. Fishing is important. The city was reconquered (1233) from the Moors by James I of Aragon. In 1251 it was moved 2 mi (3.2 km) from a hilltop to its present site on a plain (hence "de la Plana").