| Castleton to Montalegre | 853.32 mi (1,373.29 km) |
| Castleton to Montemor-o-Novo | 1,071.14 mi (1,723.83 km) |
| Castleton to Montemor-o-Velho | 976.12 mi (1,570.92 km) |
| Castleton to Montijo | 1,077.99 mi (1,734.85 km) |
| Castleton to Mortagua | 952.00 mi (1,532.09 km) |
| Castleton to Moura | 1,097.00 mi (1,765.45 km) |
| Castleton to Murtosa | 937.81 mi (1,509.25 km) |
| Castleton to Nazare | 1,019.38 mi (1,640.54 km) |
| Castleton to Nelas | 941.26 mi (1,514.82 km) |
| Castleton to Obidos | 1,036.79 mi (1,668.55 km) |
| Castleton to Odemira | 1,148.09 mi (1,847.68 km) |
| Castleton to Odivelas | 1,074.84 mi (1,729.78 km) |
| Castleton to Oeiras | 1,083.96 mi (1,744.46 km) |
| Castleton to Olhao | 1,176.24 mi (1,892.98 km) |
| Castleton to Oliveira de Azemeis | 928.39 mi (1,494.11 km) |
