| Potters Bar to Olivares | 1,028.67 mi (1,655.49 km) |
| Potters Bar to Olivenza | 959.02 mi (1,543.39 km) |
| Potters Bar to Olot | 669.33 mi (1,077.18 km) |
| Potters Bar to Onate | 607.65 mi (977.92 km) |
| Potters Bar to Onda | 810.85 mi (1,304.94 km) |
| Potters Bar to Onteniente | 889.87 mi (1,432.10 km) |
| Potters Bar to Orihuela | 941.25 mi (1,514.80 km) |
| Potters Bar to Osuna | 1,027.80 mi (1,654.09 km) |
| Potters Bar to Ourense | 740.18 mi (1,191.21 km) |
| Potters Bar to Oviedo | 633.30 mi (1,019.20 km) |
| Potters Bar to Paiporta | 847.86 mi (1,364.51 km) |
| Potters Bar to Pajara | 1,766.31 mi (2,842.61 km) |
| Potters Bar to Palafolls | 706.58 mi (1,137.13 km) |
| Potters Bar to Palafrugell | 693.86 mi (1,116.66 km) |
| Potters Bar to Palamos | 698.34 mi (1,123.86 km) |
