The calculated distance (air line) between San Juan Opico and Antiguo Cuscatlán is approximately 16 miles respectively 26 kilometers.
By car or train, the actual journey to Antiguo Cuscatlán is certainly longer, as only the direct route (as the crow flies) between San Juan Opico and Antiguo Cuscatlán has been calculated here.
Air line (approximately)
26 kilometers
14 nautical miles