The calculated distance (air line) between Horta-Guinardó and Ciutat Vella is approximately 3 miles respectively 4 kilometers.
By car or train, the actual journey to Ciutat Vella is certainly longer, as only the direct route (as the crow flies) between Horta-Guinardó and Ciutat Vella has been calculated here.
Air line (approximately)
4 kilometers
2 nautical miles