Colchis (a historical region and ancient Georgian kingdom on the coast of the Black Sea in the South Caucasus on the border between Europe and Asia, corresponding to what is now western Georgia (including Abkhazia), as well as parts of Russia and Turkey)
Colombier (a village in Allier department, Auvergne-Rhône-Alpes, France); Colombier (a village in Dordogne department, Nouvelle-Aquitaine, France); Colombier (a village in Haute-Saône department, Bourgogne-Franche-Comté, France)
Colorado, Colorado River (a major river of western North America, running from the Rocky Mountains in the United States to the Gulf of California in Mexico); Colorado (a state in the western United States, the 38th state)
Comoros (a country and group of islands in the Indian Ocean off the coast of East Africa); Comoros (an archipelago consisting of the Union of the Comoros and the French overseas department of Mayotte)