| Name of the place | CERL ID of a place | Country | Longitude | Latitude | |
|---|---|---|---|---|---|
| Clermont-Ferrand | cnl00008294 | France | 3.08 | 45.78 | |
| Clermont-sur-Oise | cnl00022744 | France | — | — | |
| Clifton (Lancashire) | — | England | -2.809 | 53.767 | |
| Clogher | cnl00027655 | Northern Ireland | — | — | |
| Clonmel | cnl00002913 | Ireland | 9.0 | 52.3527777777778 | |
| Cluain Fearta | cnl00050718 | Ireland | -8.1275 | 53.1991 | |
| Cluj | cnl00017035 | Romania | 23.6 | 46.77 | |
| Cluny | cnl00008307 | France | 4.65 | 46.4297222222222 | |
| Cluzel (Haute-Loire) | cnl00020989 | France | 3.5289 | 45.1217 | |
| Coburg | cnl00007929 | Germany | 10.97 | 50.27 | |
| Cockermouth | cnl00020378 | England | -3.362 | 54.6613 | |
| Codogno | — | Italy | — | — | |
| Coesfeld | cnl00008314 | Germany | 7.15 | 51.9297222222222 | |
| Cognac | cnl00027039 | France | -0.333055555555556 | 45.7 | |
| Coimbra | cnl00008319 | Portugal | -8.42 | 40.2 | |
| Colchester | cnl00008322 | England | 0.9 | 51.88 | |
| Colditz | cnl00008324 | Germany | 12.82 | 51.13 | |
| Coleraine | cnl00025370 | Ireland | — | — | |
| Coligny (Ain) | cnl00000329 | France | 5.34972222222222 | 46.3830555555556 | |
| Colinton (Edinburgh) | cnl00021593 | Scotland | -3.25 | 55.908333 | |
| Cölln | cnl00024569 | Germany | — | — | |
| Colmar | cnl00030866 | France | 7.36 | 48.0794444444444 | |
| Colmar [non-CERL] | — | — | — | — | |
| Cologne [non-CERL] | — | — | — | — | |
| Cologne [non-CERL] | — | — | — | — |