| Difficult Run to Bollullos par del Condado | 3,748.33 mi (6,032.36 km) |
| Difficult Run to Bormujos | 3,770.78 mi (6,068.48 km) |
| Difficult Run to Brenes | 3,775.30 mi (6,075.76 km) |
| Difficult Run to Brunete | 3,784.61 mi (6,090.75 km) |
| Difficult Run to Bueu | 3,504.56 mi (5,640.04 km) |
| Difficult Run to Bullas | 3,966.44 mi (6,383.36 km) |
| Difficult Run to Bunol | 3,967.06 mi (6,384.37 km) |
| Difficult Run to Burela de Cabo | 3,537.86 mi (5,693.64 km) |
| Difficult Run to Burgos | 3,745.01 mi (6,027.01 km) |
| Difficult Run to Burjasot | 3,982.80 mi (6,409.70 km) |
| Difficult Run to Burriana | 3,986.14 mi (6,415.08 km) |
| Difficult Run to Cabanaquinta | 3,636.65 mi (5,852.63 km) |
| Difficult Run to Cabanillas del Campo | 3,814.19 mi (6,138.35 km) |
| Difficult Run to Cabra | 3,848.69 mi (6,193.88 km) |
| Difficult Run to Caceres | 3,695.37 mi (5,947.12 km) |
