| Arouca to Oerlinghausen | 1,103.67 mi (1,776.18 km) |
| Arouca to Oestrich-Winkel | 1,002.30 mi (1,613.05 km) |
| Arouca to Offenburg | 946.84 mi (1,523.79 km) |
| Arouca to Oftersheim | 1,002.47 mi (1,613.31 km) |
| Arouca to Ohrdruf | 1,134.88 mi (1,826.42 km) |
| Arouca to Ohringen | 1,033.35 mi (1,663.02 km) |
| Arouca to Olbernhau | 1,230.92 mi (1,980.97 km) |
| Arouca to Olching | 1,081.63 mi (1,740.71 km) |
| Arouca to Oldenburg | 1,140.16 mi (1,834.92 km) |
| Arouca to Oldenburg in Holstein | 1,275.12 mi (2,052.11 km) |
| Arouca to Olfen | 1,049.87 mi (1,689.61 km) |
| Arouca to Olpe | 1,035.79 mi (1,666.95 km) |
| Arouca to Olsberg | 1,072.10 mi (1,725.37 km) |
| Arouca to Oranienburg | 1,294.25 mi (2,082.89 km) |
| Arouca to Ortenberg | 1,054.93 mi (1,697.75 km) |
