The De Mond Nature Reserve, in the Overberg between Struisbaai and Arniston, Western Cape, South Africa, has been a Ramsar site wetland since 1986.
The reserve covers the mouth of the Heuningnes River and covers . Shifting dunes block the river's mouth and serve as a breeding ground for various species of birds. The area is also a habitat for reptiles, crustaceans, and seahorses.
It is composed of different coastal vegetation communities, including dune milkwood forests and salt marshes making up the estuarine environment.