| Name of the place | CERL ID of a place | Country | Longitude | Latitude | |
|---|---|---|---|---|---|
| Lycopolis | cnl00021502 | Egypt | — | — | |
| Lyme Handley (Cheshire) | cnl00050725 | England | -2.054 | 53.339 | |
| Lyon | cnl00011383 | France | 4.85 | 45.75 | |
| Lyon [non-CERL] | — | — | — | — | |
| Lyon [non-CERL] [non-CERL] | — | — | — | — | |
| Lyons-la-Forêt | cnl00018000 | France | 1.4769 | 49.4003 | |
| Maarheze | — | Netherlands | 5.613333 | 51.310833 | |
| Maarssen | cnl00005276 | Netherlands | 5.03305555555556 | 52.1330555555556 | |
| Maassluis | cnl00005301 | Netherlands | 4.23305555555556 | 51.9330555555556 | |
| Maastricht | cnl00016317 | Netherlands | 5.69 | 50.85 | |
| Maastricht [non-CERL] | — | — | — | — | |
| Macerata | cnl00016127 | Italy | 13.4497222222222 | 43.2997222222222 | |
| Mackworth (Derbyshire) | cnl00019921 | England | -1.535 | 52.935 | |
| Macon | cnl00011430 | — | 4.83 | 46.2997222222222 | |
| Macôn | cnl00018919 | France | 4.8313 | 46.3063 | |
| Madagascar | cnl00022631 | Madagascar | 47.5361 | -18.9137 | |
| Madeira | — | Portugal | -16.2749989 | 32.37166518 | |
| Madrid | cnl00028773 | Spain | -3.7 | 40.42 | |
| Madrid [non-CERL] | — | — | — | — | |
| Madrigal de las Altas Torres | cnl00019812 | Spain | — | — | |
| Magdeburg | cnl00028054 | Germany | 11.6694444444444 | 52.17 | |
| Magny-les-Hameaux | cnl00027062 | France | 2.08305555555556 | 48.7330555555556 | |
| Mahon | — | Spain | — | — | |
| Mähren | cnl00028063 | — | — | — | |
| Maidenhead | cnl00046198 | England | -0.719722222222222 | 51.5227777777778 |