The French Riviera, known in French as the Côte d'Azur, is the Mediterranean coastline of the southeast corner of France. There is no official boundary, but it is considered to be the coastal area of the Alpes-Maritimes department, extending from the rock formation Massif de l'Esterel to Menton, at the France–Italy border, although some other sources place the western boundary further west around Saint-Tropez or even Toulon. The coast is entirely within the Provence-Alpes-Côte d'Azur region of France. The Principality of Monaco is a semi-enclave within the region, surrounded on three sides by France and fronting the Mediterranean. The French Riviera contains the seaside resorts of Cap-d'Ail, Beaulieu-sur-Mer, Saint-Jean-Cap-Ferrat, Villefranche-sur-Mer, Antibes, Juan-les-Pins, Cannes, and Théoule-sur-Mer.