Gros Îlet, also known as Îlet Mandoline because of its shape and formerly called Îlet à Vaches, lies in Génipa Bay opposite Pointe Vatable and belongs to the commune of Les Trois-Îlets.
Tourism and heritage sources describe it as an uninhabited islet roughly 600 to 650 metres long. It is now part of the Parc Naturel Régional de Martinique.