The calculated distance (air line) between Castelló de la Plana and Oropesa del Mar is approximately 12 miles respectively 20 kilometers.
By car or train, the actual journey to Oropesa del Mar is certainly longer, as only the direct route (as the crow flies) between Castelló de la Plana and Oropesa del Mar has been calculated here.
Air line (approximately)
20 kilometers
11 nautical miles