Réserve naturelle nationale de Lilleau des Niges, National nature reserve in Les Portes-en-Ré, France.

The Réserve naturelle nationale de Lilleau des Niges covers 118.89 hectares of former salt marshes and mudflats at the northern end of Île de Ré, in the commune of Les Portes-en-Ré, with a further 108.77-hectare protection perimeter. Straight embankments and ditches divide the marsh into basins, and a broad turquoise channel curves around its edge. Two white herons often stand in the shallows.

The site was classified as a national nature reserve in 1980, protecting 121 hectares of salt marshes and mudflats on the northern Île de Ré. The landscape had been shaped by salt production, and the old port of Les Portes-en-Ré was once the commune's only access. Two salt warehouses were built around 1910; one survives and now houses the Maison du Fier, inaugurated after 1997.

The visitor center occupies a former salt storage building and displays exhibits about the birds and natural life of the island. Here you discover which species pass through and how human activity shaped this landscape over time.

You can walk through the reserve on a path roughly 2 kilometers long that runs along its southern edge with good viewing spots. Guided tours are available to help you identify bird species and learn how to observe them properly.

This location serves as a crucial stopover for migrating birds traveling between northern and southern Europe, especially in spring and fall. Observers can spot thousands of birds from many different species on a single day here.