| Castlebar to Beyne-Heusay | 669.50 mi (1,077.46 km) |
| Castlebar to Bierbeek | 628.17 mi (1,010.94 km) |
| Castlebar to Bilzen | 656.98 mi (1,057.31 km) |
| Castlebar to Binche | 617.93 mi (994.46 km) |
| Castlebar to Bissegem | 567.71 mi (913.64 km) |
| Castlebar to Blankenberge | 549.61 mi (884.51 km) |
| Castlebar to Blegny | 671.34 mi (1,080.41 km) |
| Castlebar to Bocholt | 651.16 mi (1,047.94 km) |
| Castlebar to Boechout | 607.98 mi (978.45 km) |
| Castlebar to Bonheiden | 613.20 mi (986.85 km) |
| Castlebar to Boom | 605.19 mi (973.95 km) |
| Castlebar to Boortmeerbeek | 615.94 mi (991.25 km) |
| Castlebar to Borgerhout | 604.61 mi (973.02 km) |
| Castlebar to Borgloon | 651.93 mi (1,049.18 km) |
| Castlebar to Bornem | 599.42 mi (964.68 km) |
