Input (grade 10): Saint-Martin-de-Castillon is a commune in the Vaucluse department in the Provence-Alpes-C Ã te d'Azur region in southeastern France.
Output (grade 5): Saint-Martin-de-Castillon is a commune. It is found in the region Provence-Alpes-C Ã te d'Azur in the Vaucluse department in the south of France.