| Merthyr Tudful to Lowell (Indiana) | 3,834.37 mi (6,170.82 km) |
| Merthyr Tudful to Lowell (Massachusetts) | 3,132.40 mi (5,041.10 km) |
| Merthyr Tudful to Lower Burrell (Pennsylvania) | 3,561.35 mi (5,731.43 km) |
| Merthyr Tudful to Lowes Island (Virginia) | 3,533.40 mi (5,686.46 km) |
| Merthyr Tudful to Lubbock (Texas) | 4,769.82 mi (7,676.29 km) |
| Merthyr Tudful to Lufkin (Texas) | 4,607.67 mi (7,415.33 km) |
| Merthyr Tudful to Luling (Louisiana) | 4,503.47 mi (7,247.64 km) |
| Merthyr Tudful to Lumberton (North Carolina) | 3,804.85 mi (6,123.31 km) |
| Merthyr Tudful to Lumberton (Texas) | 4,641.34 mi (7,469.51 km) |
| Merthyr Tudful to Lutz (Florida) | 4,264.01 mi (6,862.26 km) |
| Merthyr Tudful to Lynbrook (New York) | 3,311.91 mi (5,330.00 km) |
| Merthyr Tudful to Lynchburg (Virginia) | 3,683.31 mi (5,927.71 km) |
| Merthyr Tudful to Lynden (Washington) | 4,612.74 mi (7,423.48 km) |
| Merthyr Tudful to Lyndhurst (Ohio) | 3,591.24 mi (5,779.55 km) |
| Merthyr Tudful to Lyndon (Kentucky) | 3,902.61 mi (6,280.65 km) |
