The calculated distance (air line) between Unión de Reyes and La Habana Vieja is approximately 57 miles respectively 92 kilometers.
By car or train, the actual journey to La Habana Vieja is certainly longer, as only the direct route (as the crow flies) between Unión de Reyes and La Habana Vieja has been calculated here.
Air line (approximately)
92 kilometers
49 nautical miles