| Potomac to Quarteira | 3,667.42 mi (5,902.15 km) |
| Potomac to Queluz | 3,562.23 mi (5,732.86 km) |
| Potomac to Reguengos de Monsaraz | 3,657.26 mi (5,885.79 km) |
| Potomac to Resende | 3,563.51 mi (5,734.91 km) |
| Potomac to Ribeira Brava | 3,335.83 mi (5,368.50 km) |
| Potomac to Ribeira Grande | 2,760.38 mi (4,442.40 km) |
| Potomac to Rio de Mouro | 3,558.47 mi (5,726.81 km) |
| Potomac to Rio Maior | 3,562.96 mi (5,734.03 km) |
| Potomac to Rio Tinto | 3,532.87 mi (5,685.60 km) |
| Potomac to Sabugal | 3,626.07 mi (5,835.59 km) |
| Potomac to Sacavem | 3,569.04 mi (5,743.81 km) |
| Potomac to Salvaterra de Magos | 3,578.91 mi (5,759.69 km) |
| Potomac to Santa Comba Dao | 3,574.54 mi (5,752.67 km) |
| Potomac to Santa Cruz | 3,348.95 mi (5,389.62 km) |
| Potomac to Santa Iria da Azoia | 3,568.47 mi (5,742.90 km) |
