| Watertown to Orbetello | 4,167.48 mi (6,706.92 km) |
| Watertown to Oria | 4,515.08 mi (7,266.32 km) |
| Watertown to Oristano | 4,153.23 mi (6,683.97 km) |
| Watertown to Orta Nova | 4,400.45 mi (7,081.84 km) |
| Watertown to Orte | 4,216.02 mi (6,785.03 km) |
| Watertown to Ortona | 4,304.41 mi (6,927.28 km) |
| Watertown to Orvieto | 4,194.35 mi (6,750.16 km) |
| Watertown to Orzinuovi | 4,002.32 mi (6,441.11 km) |
| Watertown to Osimo | 4,221.39 mi (6,793.67 km) |
| Watertown to Ospitaletto | 4,002.36 mi (6,441.18 km) |
| Watertown to Ostuni | 4,503.14 mi (7,247.11 km) |
| Watertown to Ottaviano | 4,368.51 mi (7,030.44 km) |
| Watertown to Ovada | 3,976.88 mi (6,400.17 km) |
| Watertown to Ozieri | 4,144.81 mi (6,670.42 km) |
| Watertown to Paceco | 4,403.50 mi (7,086.75 km) |
