Here is a route that goes around the lake as close as possible, favoring small roads and cycle paths as much as possible. Guaranteed with 100% paved roads. The small points at Passay, St Aignan de Grand-lieu and Ste Lumine de Coutais go inwards to open windows, more or less passable depending on the season, with a view of the lake.
Due to the very low slope of the land it covers, Lake Grand-Lieu is characterized by a very fluctuating surface area, a shallow depth, and a functioning that evokes rather that of large shallow lakes such as Lake Chad, than that of most of the other great lakes of France. In winter, it is the largest natural plain lake in France.