 Only the westernmost and north-eastern extremities of the island remain residential today, and the latter area preserves some vestiges of its 16th-century canonic houses.Purely residential in nature, this island's first use was for the grazing of market cattle and the stocking of wood.One of France's first examples of urban planning, it was mapped and built from end to end during the 17th-century reigns of Henri IV and Louis XIII.