The calculated distance (air line) between Cartagena and Castelló de la Plana is approximately 172 miles respectively 277 kilometers.
By car or train, the actual journey to Castelló de la Plana is certainly longer, as only the direct route (as the crow flies) between Cartagena and Castelló de la Plana has been calculated here.
Air line (approximately)
277 kilometers
150 nautical miles