The Zwin is a nature reserve on the border between Belgium and the Netherlands on the North Sea coast. Most of the reserve is in fact the entrance to a former tidal inlet, which used to connect the North Sea with the Bruges and Sluis ports in the Middle Ages. The nature reserve was established in 1952, with its bigger part, 158 hectares, in Belgium and only 33 hectares in the Netherlands. The reserve is known for its large diversity of salt-resistant plants, including sea lavender, and a huge number of bird species, making it a heaven for bird watchers. The reserve has a small zoo that is a home to a number of important domestic birds. It is one of the rare places in Belgium to have a significant white stork population.