Île Saint-Louis is an island of 1600s houses in the Seine, built as a single property deal and never redeveloped since. The shops, the restaurants and the ice cream queue are all on one street, rue Saint-Louis-en-l'Île, which runs the length of it. Turn into any cross street and the noise stops within thirty paces. The quays carry almost no trade: plain stone fronts, plane trees, and steps down to a ledge at the water where people sit. About two thousand people live here, a quarter of the number packed in during the 1850s.
In 1614 the Crown handed two empty islets in the Seine to a contractor, Christophe Marie. The grass belonged to Notre-Dame's clergy; cattle grazed it and cloth was spread on it to bleach. Marie had to fill the channel between the islets, build lasting bridges to the banks and face the new edges in cut stone, and in exchange he could sell the new ground in plots. No king designed this place: Marie and two financiers laid it out themselves, to make money on it. Within about fifty years all eleven hectares were built up.