The calculated distance (air line) between Unión de Reyes and Diez de Octubre is approximately 56 miles respectively 90 kilometers.
By car or train, the actual journey to Diez de Octubre is certainly longer, as only the direct route (as the crow flies) between Unión de Reyes and Diez de Octubre has been calculated here.
Air line (approximately)
90 kilometers
49 nautical miles