| Duncan to Quarteira | 4,828.81 mi (7,771.22 km) |
| Duncan to Queluz | 4,718.07 mi (7,593.00 km) |
| Duncan to Reguengos de Monsaraz | 4,811.55 mi (7,743.44 km) |
| Duncan to Resende | 4,704.21 mi (7,570.70 km) |
| Duncan to Ribeira Brava | 4,519.21 mi (7,272.96 km) |
| Duncan to Ribeira Grande | 3,939.68 mi (6,340.30 km) |
| Duncan to Rio de Mouro | 4,714.34 mi (7,587.00 km) |
| Duncan to Rio Maior | 4,715.32 mi (7,588.57 km) |
| Duncan to Rio Tinto | 4,674.36 mi (7,522.65 km) |
| Duncan to Sabugal | 4,769.34 mi (7,675.51 km) |
| Duncan to Sacavem | 4,724.38 mi (7,603.16 km) |
| Duncan to Salvaterra de Magos | 4,732.58 mi (7,616.35 km) |
| Duncan to Santa Comba Dao | 4,719.63 mi (7,595.51 km) |
| Duncan to Santa Cruz | 4,532.20 mi (7,293.88 km) |
| Duncan to Santa Iria da Azoia | 4,723.54 mi (7,601.80 km) |
