The average rent for a one-bedroom apartment in Castellón de la Plana typically ranges from €400 to €600 per month. Prices can vary based on factors such as location, size, and condition of the apartment. For instance, a one-bedroom apartment in the city center might cost around €550, while a similar unit in a less central area could be found for €450. Newer developments or those with modern amenities may push the price closer to €600, especially if they are near popular attractions or public transport. In more residential neighborhoods, rents may drop slightly, providing options for those seeking affordability. It's also worth noting that during peak tourist seasons, rental prices can fluctuate, affecting the supply and demand dynamics in the market.