| Pen-y-Bont ar Ogwr to Nuth | 411.27 mi (661.87 km) |
| Pen-y-Bont ar Ogwr to Oegstgeest | 346.38 mi (557.45 km) |
| Pen-y-Bont ar Ogwr to Oirschot | 381.61 mi (614.14 km) |
| Pen-y-Bont ar Ogwr to Oisterwijk | 377.01 mi (606.74 km) |
| Pen-y-Bont ar Ogwr to Oldebroek | 408.30 mi (657.10 km) |
| Pen-y-Bont ar Ogwr to Oldenzaal | 451.10 mi (725.97 km) |
| Pen-y-Bont ar Ogwr to Ommen | 430.38 mi (692.63 km) |
| Pen-y-Bont ar Ogwr to Oosterend | 420.47 mi (676.67 km) |
| Pen-y-Bont ar Ogwr to Oosterhout | 362.14 mi (582.80 km) |
| Pen-y-Bont ar Ogwr to Oosterwolde | 429.52 mi (691.24 km) |
| Pen-y-Bont ar Ogwr to Oostzaan | 365.60 mi (588.38 km) |
| Pen-y-Bont ar Ogwr to Opmeer | 370.97 mi (597.01 km) |
| Pen-y-Bont ar Ogwr to Oss | 390.18 mi (627.93 km) |
| Pen-y-Bont ar Ogwr to Oud-Beijerland | 342.44 mi (551.10 km) |
| Pen-y-Bont ar Ogwr to Oudenbosch | 347.99 mi (560.04 km) |
