The calculated distance (air line) between Santa Coloma de Cervelló and Castelldefels is approximately 7 miles respectively 11 kilometers.
By car or train, the actual journey to Castelldefels is certainly longer, as only the direct route (as the crow flies) between Santa Coloma de Cervelló and Castelldefels has been calculated here.
Air line (approximately)
11 kilometers
6 nautical miles