| Irthlingborough to Cascais | 1,031.52 mi (1,660.07 km) |
| Irthlingborough to Castelo Branco | 924.03 mi (1,487.09 km) |
| Irthlingborough to Castro Daire | 861.32 mi (1,386.17 km) |
| Irthlingborough to Celorico de Basto | 831.56 mi (1,338.27 km) |
| Irthlingborough to Chamusca | 971.79 mi (1,563.94 km) |
| Irthlingborough to Chaves | 798.51 mi (1,285.07 km) |
| Irthlingborough to Cinfaes | 852.30 mi (1,371.65 km) |
| Irthlingborough to Coimbra | 915.12 mi (1,472.74 km) |
| Irthlingborough to Condeixa-a-Nova | 922.55 mi (1,484.70 km) |
| Irthlingborough to Corroios | 1,031.90 mi (1,660.68 km) |
| Irthlingborough to Coruche | 998.12 mi (1,606.32 km) |
| Irthlingborough to Costa de Caparica | 1,031.58 mi (1,660.17 km) |
| Irthlingborough to Covilha | 893.51 mi (1,437.97 km) |
| Irthlingborough to Eiras | 913.02 mi (1,469.36 km) |
| Irthlingborough to Elvas | 981.04 mi (1,578.83 km) |
