| Herndon to Cascais | 3,566.89 mi (5,740.36 km) |
| Herndon to Castelo Branco | 3,630.85 mi (5,843.29 km) |
| Herndon to Castro Daire | 3,580.97 mi (5,763.01 km) |
| Herndon to Celorico de Basto | 3,565.25 mi (5,737.72 km) |
| Herndon to Chamusca | 3,595.34 mi (5,786.14 km) |
| Herndon to Chaves | 3,581.47 mi (5,763.82 km) |
| Herndon to Cinfaes | 3,566.11 mi (5,739.10 km) |
| Herndon to Coimbra | 3,574.96 mi (5,753.34 km) |
| Herndon to Condeixa-a-Nova | 3,574.00 mi (5,751.80 km) |
| Herndon to Corroios | 3,582.40 mi (5,765.31 km) |
| Herndon to Coruche | 3,603.89 mi (5,799.90 km) |
| Herndon to Costa de Caparica | 3,577.38 mi (5,757.23 km) |
| Herndon to Covilha | 3,618.27 mi (5,823.04 km) |
| Herndon to Eiras | 3,574.40 mi (5,752.44 km) |
| Herndon to Elvas | 3,674.20 mi (5,913.06 km) |
