| Harpenden to Dendermonde | 199.29 mi (320.72 km) |
| Harpenden to Dessel | 238.48 mi (383.80 km) |
| Harpenden to Destelbergen | 186.53 mi (300.18 km) |
| Harpenden to Deurne | 210.97 mi (339.53 km) |
| Harpenden to Diepenbeek | 256.67 mi (413.07 km) |
| Harpenden to Diest | 239.87 mi (386.03 km) |
| Harpenden to Diksmuide | 148.88 mi (239.60 km) |
| Harpenden to Dilbeek | 209.98 mi (337.94 km) |
| Harpenden to Dinant | 252.66 mi (406.62 km) |
| Harpenden to Dison | 280.85 mi (451.99 km) |
| Harpenden to Dour | 204.33 mi (328.84 km) |
| Harpenden to Drongen | 181.03 mi (291.34 km) |
| Harpenden to Duffel | 215.35 mi (346.58 km) |
| Harpenden to Durbuy | 271.58 mi (437.07 km) |
| Harpenden to Ecaussinnes-Lalaing | 214.53 mi (345.25 km) |
