| Hardenberg to Opwijk | 151.80 mi (244.30 km) |
| Hardenberg to Ostend | 182.82 mi (294.22 km) |
| Hardenberg to Oud-Heverlee | 145.99 mi (234.95 km) |
| Hardenberg to Oud-Turnhout | 110.90 mi (178.47 km) |
| Hardenberg to Oudenaarde | 175.33 mi (282.17 km) |
| Hardenberg to Oudenburg | 181.45 mi (292.02 km) |
| Hardenberg to Oupeye | 135.02 mi (217.29 km) |
| Hardenberg to Overijse | 152.14 mi (244.85 km) |
| Hardenberg to Overpelt | 106.39 mi (171.21 km) |
| Hardenberg to Paal | 122.24 mi (196.73 km) |
| Hardenberg to Peer | 110.81 mi (178.33 km) |
| Hardenberg to Pepinster | 142.39 mi (229.16 km) |
| Hardenberg to Peruwelz | 192.46 mi (309.74 km) |
| Hardenberg to Perwez | 154.89 mi (249.28 km) |
| Hardenberg to Philippeville | 186.21 mi (299.68 km) |
