| Watertown Town to Opwijk | 3,463.50 mi (5,573.97 km) |
| Watertown Town to Ostend | 3,405.88 mi (5,481.24 km) |
| Watertown Town to Oud-Heverlee | 3,486.48 mi (5,610.95 km) |
| Watertown Town to Oud-Turnhout | 3,486.94 mi (5,611.68 km) |
| Watertown Town to Oudenaarde | 3,442.73 mi (5,540.54 km) |
| Watertown Town to Oudenburg | 3,410.18 mi (5,488.15 km) |
| Watertown Town to Oupeye | 3,529.26 mi (5,679.80 km) |
| Watertown Town to Overijse | 3,482.35 mi (5,604.29 km) |
| Watertown Town to Overpelt | 3,506.90 mi (5,643.81 km) |
| Watertown Town to Paal | 3,501.66 mi (5,635.37 km) |
| Watertown Town to Peer | 3,510.55 mi (5,649.68 km) |
| Watertown Town to Pepinster | 3,540.04 mi (5,697.14 km) |
| Watertown Town to Peruwelz | 3,450.39 mi (5,552.86 km) |
| Watertown Town to Perwez | 3,497.88 mi (5,629.29 km) |
| Watertown Town to Philippeville | 3,498.07 mi (5,629.60 km) |
