Marais de Brière
The Marais de Brière is located in France, north side of the Loire River estuary. It's a wild flat place composed of water pastures and reeds. The marsh disappears in MSFS2020 under a totally unreal large forest.
I offer a more realistic version of this space quickly visible after take-off from La Baule Escoublac. A small tourist flight allows you to appreciate the Saint Nazaire bridge, the Brière marsh and then the salt marshes of Guérande.