| Boulder to Zottegem | 4,840.44 mi (7,789.94 km) |
| Boulder to Zulte | 4,825.92 mi (7,766.57 km) |
| Boulder to Zwevegem | 4,827.66 mi (7,769.37 km) |
| Boulder to Zwijndrecht | 4,842.78 mi (7,793.71 km) |
| Boulder to Asenovgrad | 5,965.39 mi (9,600.37 km) |
| Boulder to Aytos | 5,996.92 mi (9,651.11 km) |
| Boulder to Balchik | 5,981.19 mi (9,625.80 km) |
| Boulder to Bankya | 5,874.81 mi (9,454.60 km) |
| Boulder to Bansko | 5,933.32 mi (9,548.75 km) |
| Boulder to Berkovitsa | 5,844.90 mi (9,406.47 km) |
| Boulder to Blagoevgrad | 5,911.42 mi (9,513.51 km) |
| Boulder to Botevgrad | 5,883.43 mi (9,468.46 km) |
| Boulder to Burgas | 6,014.48 mi (9,679.37 km) |
| Boulder to Byala Slatina | 5,856.60 mi (9,425.28 km) |
| Boulder to Chirpan | 5,968.85 mi (9,605.94 km) |
