| Potomac to Arcos de Valdevez | 3,522.77 mi (5,669.35 km) |
| Potomac to Arcozelo | 3,532.15 mi (5,684.45 km) |
| Potomac to Arganil | 3,582.41 mi (5,765.32 km) |
| Potomac to Arouca | 3,554.38 mi (5,720.22 km) |
| Potomac to Arruda dos Vinhos | 3,565.82 mi (5,738.63 km) |
| Potomac to Aveiro | 3,542.51 mi (5,701.12 km) |
| Potomac to Aver-o-Mar | 3,517.05 mi (5,660.14 km) |
| Potomac to Aves | 3,538.74 mi (5,695.05 km) |
| Potomac to Azambuja | 3,573.43 mi (5,750.89 km) |
| Potomac to Baiao | 3,558.59 mi (5,727.00 km) |
| Potomac to Barcelos | 3,521.54 mi (5,667.38 km) |
| Potomac to Barreiro | 3,574.43 mi (5,752.49 km) |
| Potomac to Batalha | 3,561.04 mi (5,730.93 km) |
| Potomac to Beja | 3,650.75 mi (5,875.32 km) |
| Potomac to Belas | 3,561.32 mi (5,731.39 km) |
