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)
the imaginary capital of the Realm of the Dolls (le royaume des poupées) in Alexandre Dumas's translation of E. T. A. Hoffmann's Nussknacker und Mausekönig (The Nutcracker and the Mouse King)