The calculated distance (air line) between Pilar de la Horadada and Cartagena is approximately 21 miles respectively 34 kilometers.
By car or train, the actual journey to Cartagena is certainly longer, as only the direct route (as the crow flies) between Pilar de la Horadada and Cartagena has been calculated here.
Air line (approximately)
34 kilometers
18 nautical miles