The calculated distance (air line) between Vila Nova de Gaia and Foz do Sousa is approximately 6 miles respectively 10 kilometers.
By car or train, the actual journey to Foz do Sousa is certainly longer, as only the direct route (as the crow flies) between Vila Nova de Gaia and Foz do Sousa has been calculated here.
Air line (approximately)
10 kilometers
5 nautical miles