Moret-sur-Loing. Moret-sur-Loing is a former commune in the Seine-et-Marne department in the Île-de-France region in north-central France. On 1 January 2015, Moret-sur-Loing and Écuelles merged becoming one commune called Orvanne, which merged into the new commune Moret-Loing-et-Orvanne on 1 January 2016. The town was a source of inspiration for Monet, Renoir and Sisley. Inhabitants of Moret-sur-Loing are called Morétains. Moret-sur-Loing is twinned with: Kilkenny, Co. Kilkenny, Ireland. Külsheim, Baden-Württemberg, Germany.