| Mastic to Orbetello | 4,150.98 mi (6,680.36 km) |
| Mastic to Oria | 4,504.19 mi (7,248.79 km) |
| Mastic to Oristano | 4,119.52 mi (6,629.73 km) |
| Mastic to Orta Nova | 4,388.76 mi (7,063.03 km) |
| Mastic to Orte | 4,202.09 mi (6,762.61 km) |
| Mastic to Ortona | 4,294.30 mi (6,911.00 km) |
| Mastic to Orvieto | 4,181.01 mi (6,728.69 km) |
| Mastic to Orzinuovi | 3,997.11 mi (6,432.73 km) |
| Mastic to Osimo | 4,214.39 mi (6,782.41 km) |
| Mastic to Ospitaletto | 3,998.17 mi (6,434.43 km) |
| Mastic to Ostuni | 4,493.11 mi (7,230.97 km) |
| Mastic to Ottaviano | 4,352.00 mi (7,003.86 km) |
| Mastic to Ovada | 3,965.51 mi (6,381.87 km) |
| Mastic to Ozieri | 4,115.10 mi (6,622.61 km) |
| Mastic to Paceco | 4,370.23 mi (7,033.21 km) |
