Castellón de la Plana is the capital of the province of Castellón, in the Valencia Region, eastern Spain. The Region covers 107.50 square kilometres and is surrounded by several mountain ranges inland plus the Mediterranean sea to the east. The main part of the city is about 30 metres above sea level and around 4 kilometres from the coast.
The municipal area lies on the intersection between parallel 40 and the Greenwich 0 meridian.