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