Karelia (a historical region of Northern Europe, located to the north of Saint Petersburg and politically split between Russia and Finland); Karelia (a republic and federal subject of Russia)
Castellet (ellipsis of Le Castellet: a commune of Var department, Provence-Alpes-Côte d'Azur, France); Castellet (ellipsis of Castellet-en-Luberon: a commune of Vaucluse department, Provence-Alpes-Côte d'Azur, France); Castellet (ellipsis of Le Castellet: a commune of Alpes-de-Haute-Provence department, Provence-Alpes-Côte d'Azur, France)
Castile (a medieval kingdom and former county in the Iberian Peninsula; the nucleus of modern Spain); Castile (a vaguely defined geographical region of central Spain generally corresponding to the regions of Old and New Castile)
Catania (a port city and comune, the capital of the Metropolitan City of Catania, Sicily, Italy); Catania (a metropolitan city of Sicily, established in 2015; in full, the Metropolitan City of Catania)