A protected nature reserve of tidal mudflats, salt marshes, dunes, and ponds straddling the Belgian-Dutch border at the northeastern tip of the Belgian coast. More than half of all bird species ever recorded in Belgium have been seen here: avocets, spoonbills, marsh harriers, oystercatchers, and enormous flocks of waders on passage in autumn. The reserve is managed jointly by Belgium and the Netherlands.
The visitor centre at the Belgian entrance has interactive exhibitions on the ecology of the site and the Zwin's geological history. Boardwalks lead out into the marshes, and several observation hides are positioned along the main watercourses. Spring and autumn migration are the best times; summer has breeding birds but is often crowded. The entrance fee is modest and the visit is easily combined with a walk along the Het Zoute beach strip nearby.