The Site is one of the least damaged dune system of the Netherlands. It is located between Oostvoorne and Harlingvliet, just 20 kilometres south of The Hague. In 2014, the boundary was adjusted to that of the Natura 2000 site, including the addition of a new area of 45 hectares. The area includes two lakes – Breedewater and Quackjeswater – and mesotrophic dune slacks surrounded by alder woodland and wet dune valleys. The Site supports rich vegetation including endangered plant species such as water germander and fen orchid, and is of particular importance for many breeding birds such as the Eurasian spoonbill (Platalea leucorodia) and great cormorant (Phalacrocorax carbo). The dunes play an important role in shoreline stabilization and water purification. Land use is dedicated to water management, tourism, conservation and research. The main factors adversely affecting the Site’s ecological character are industrialization, urbanization and tourism.