| Helensburgh to Oliveira de Frades | 1,068.58 mi (1,719.71 km) |
| Helensburgh to Oliveira do Bairro | 1,084.45 mi (1,745.26 km) |
| Helensburgh to Oliveira do Hospital | 1,091.12 mi (1,755.99 km) |
| Helensburgh to Ourem | 1,144.27 mi (1,841.53 km) |
| Helensburgh to Ovar | 1,061.48 mi (1,708.29 km) |
| Helensburgh to Pacos de Ferreira | 1,032.41 mi (1,661.50 km) |
| Helensburgh to Palmela | 1,220.83 mi (1,964.73 km) |
| Helensburgh to Paredes | 1,036.50 mi (1,668.08 km) |
| Helensburgh to Paredes de Coura | 989.46 mi (1,592.37 km) |
| Helensburgh to Penacova | 1,099.82 mi (1,769.99 km) |
| Helensburgh to Penafiel | 1,035.74 mi (1,666.86 km) |
| Helensburgh to Peniche | 1,170.89 mi (1,884.37 km) |
| Helensburgh to Peso da Regua | 1,035.25 mi (1,666.07 km) |
| Helensburgh to Pinhal Novo | 1,216.53 mi (1,957.81 km) |
| Helensburgh to Pinhel | 1,057.79 mi (1,702.35 km) |
