| Harpenden to Ondokuzmayis | 1,845.20 mi (2,969.57 km) |
| Harpenden to Ordu | 1,942.05 mi (3,125.42 km) |
| Harpenden to Ortahisar | 1,915.57 mi (3,082.82 km) |
| Harpenden to Ortakent | 1,683.59 mi (2,709.47 km) |
| Harpenden to Ortaklar | 1,653.30 mi (2,660.73 km) |
| Harpenden to Ortakoy | 1,876.28 mi (3,019.59 km) |
| Harpenden to Ortakoy | 1,860.56 mi (2,994.29 km) |
| Harpenden to Osmaneli | 1,640.14 mi (2,639.55 km) |
| Harpenden to Osmaniye | 2,042.59 mi (3,287.23 km) |
| Harpenden to Ozdere | 1,632.37 mi (2,627.05 km) |
| Harpenden to Palu | 2,124.58 mi (3,419.18 km) |
| Harpenden to Pamukkale | 1,715.02 mi (2,760.05 km) |
| Harpenden to Patnos | 2,225.53 mi (3,581.64 km) |
| Harpenden to Pazar | 1,905.34 mi (3,066.35 km) |
| Harpenden to Pazarcik | 2,067.17 mi (3,326.78 km) |
