| Niederkassel to Olivenza | 1,084.06 mi (1,744.62 km) |
| Niederkassel to Olot | 634.22 mi (1,020.67 km) |
| Niederkassel to Onate | 697.47 mi (1,122.46 km) |
| Niederkassel to Onda | 828.36 mi (1,333.12 km) |
| Niederkassel to Onteniente | 908.24 mi (1,461.66 km) |
| Niederkassel to Orihuela | 962.32 mi (1,548.71 km) |
| Niederkassel to Osuna | 1,112.22 mi (1,789.94 km) |
| Niederkassel to Ourense | 915.64 mi (1,473.58 km) |
| Niederkassel to Oviedo | 793.31 mi (1,276.70 km) |
| Niederkassel to Paiporta | 865.64 mi (1,393.11 km) |
| Niederkassel to Pajara | 1,902.68 mi (3,062.07 km) |
| Niederkassel to Palafolls | 664.04 mi (1,068.67 km) |
| Niederkassel to Palafrugell | 641.74 mi (1,032.77 km) |
| Niederkassel to Palamos | 646.97 mi (1,041.20 km) |
| Niederkassel to Palencia | 818.61 mi (1,317.43 km) |
