Réserve naturelle nationale du Platier d'Oye, National nature reserve in Oye-Plage, France

Réserve naturelle nationale du Platier d'Oye covers 391 hectares on the coast of Oye-Plage between Calais and Dunkirk, on the left bank of the Aa estuary. It has three parts: 3.5 km of foreshore and dunes, an estuarine system of mudflats and salt meadows, and a polder of wet grasslands behind the dune belt. The land lies below 2 m altitude; 250 hectares are maritime public domain.

The reserve was established in 1987 to protect an essential migration route for birds from northern Europe. Its creation recognized that this coastal area was critical for seasonal bird movements.

The reserve's name comes from the 'platier', the flat foreshore exposed at low tide. Highland cattle and ponies graze the polder meadows to keep them open for nesting waders, and ponds dug in the polder hold wintering ducks. Guided visits are run by the managing syndicate EDEN 62, and a waymarked trail with observation points lets visitors watch the birds.

The site is accessible via marked walking trails, including a path through the polder area with a wheelchair-accessible section. Visitors should bring weather-appropriate clothing and watch for wet or muddy ground conditions that vary by season.

The reserve's 391 hectares include 250 hectares of maritime public domain, and its three parts are the 3.5-kilometre beach and dunes, the Aa estuary with mudflats and salt meadows, and the polder behind the dune belt. Highland cattle and ponies graze the wet meadows to keep them open for nesting waders.