| Castro Valley to Opwijk | 5,499.76 mi (8,851.01 km) |
| Castro Valley to Ostend | 5,450.32 mi (8,771.45 km) |
| Castro Valley to Oud-Heverlee | 5,520.41 mi (8,884.24 km) |
| Castro Valley to Oud-Turnhout | 5,503.66 mi (8,857.29 km) |
| Castro Valley to Oudenaarde | 5,489.33 mi (8,834.22 km) |
| Castro Valley to Oudenburg | 5,454.83 mi (8,778.70 km) |
| Castro Valley to Oupeye | 5,554.33 mi (8,938.83 km) |
| Castro Valley to Overijse | 5,519.29 mi (8,882.44 km) |
| Castro Valley to Overpelt | 5,520.96 mi (8,885.13 km) |
| Castro Valley to Paal | 5,523.64 mi (8,889.44 km) |
| Castro Valley to Peer | 5,526.45 mi (8,893.95 km) |
| Castro Valley to Pepinster | 5,566.72 mi (8,958.77 km) |
| Castro Valley to Peruwelz | 5,506.28 mi (8,861.50 km) |
| Castro Valley to Perwez | 5,535.65 mi (8,908.76 km) |
| Castro Valley to Philippeville | 5,550.58 mi (8,932.79 km) |
