| Boulder to Ayamonte | 4,989.36 mi (8,029.61 km) |
| Boulder to Azcoitia | 4,949.73 mi (7,965.83 km) |
| Boulder to Azpeitia | 4,951.41 mi (7,968.53 km) |
| Boulder to Azuqueca de Henares | 5,022.85 mi (8,083.49 km) |
| Boulder to Badajoz | 4,937.83 mi (7,946.67 km) |
| Boulder to Badalona | 5,205.50 mi (8,377.45 km) |
| Boulder to Baena | 5,105.34 mi (8,216.25 km) |
| Boulder to Baeza | 5,125.75 mi (8,249.10 km) |
| Boulder to Bailen | 5,108.70 mi (8,221.65 km) |
| Boulder to Balaguer | 5,133.43 mi (8,261.46 km) |
| Boulder to Banolas | 5,195.08 mi (8,360.68 km) |
| Boulder to Baranain | 4,991.51 mi (8,033.06 km) |
| Boulder to Barbadanes | 4,758.77 mi (7,658.50 km) |
| Boulder to Barbastro | 5,095.75 mi (8,200.82 km) |
| Boulder to Barcelona | 5,205.60 mi (8,377.60 km) |
