Het Zwin is an area along the coast of the North Sea between Belgium and the Netherlands. It is a protected bird reserve. There are 2 ways of visiting it. Either hike along the beach from Knokke/Le Zoute and here you are skirting the Zwin without actually being in it. It is a fun and beautiful walk on the wide beaches.
Or you can enter the Zwin from the land side at a gate where there is a fee. Inside there are very large enclosures (volieres) where many birds are displayed. There are even storks nesting on the tops of very high lamp posts.
I like to take the beach route and then ford the inlet that separates Belgium from Holland. This can only be safely done at low tide. In Holland, visit one of the dune hotels and enjoy koffee and apelbol!