| Potomac to Cascais | 3,556.18 mi (5,723.12 km) |
| Potomac to Castelo Branco | 3,620.19 mi (5,826.13 km) |
| Potomac to Castro Daire | 3,570.33 mi (5,745.90 km) |
| Potomac to Celorico de Basto | 3,554.63 mi (5,720.63 km) |
| Potomac to Chamusca | 3,584.65 mi (5,768.94 km) |
| Potomac to Chaves | 3,570.87 mi (5,746.77 km) |
| Potomac to Cinfaes | 3,555.48 mi (5,722.00 km) |
| Potomac to Coimbra | 3,564.30 mi (5,736.19 km) |
| Potomac to Condeixa-a-Nova | 3,563.34 mi (5,734.64 km) |
| Potomac to Corroios | 3,571.69 mi (5,748.07 km) |
| Potomac to Coruche | 3,593.19 mi (5,782.68 km) |
| Potomac to Costa de Caparica | 3,566.67 mi (5,739.99 km) |
| Potomac to Covilha | 3,607.62 mi (5,805.91 km) |
| Potomac to Eiras | 3,563.74 mi (5,735.28 km) |
| Potomac to Elvas | 3,663.52 mi (5,895.86 km) |
