Duinen Vlieland is a small island in the Wadden Sea, characterized by an extensive area of sand dunes, conifer crops and embanked brackish lagoons important for maintaining the biodiversity in the Atlantic biogeographic region. The Site was formerly part of Ramsar Site 1252 (Waddeneilanden, Noordzeekustzone, Breebaart) which was divided into six Sites following Natura 2000 borders in 2014. The Site is of particular importance for breeding and non-breeding bird species. Some of these, such as the great cormorant and Eurasian spoonbill, gather in particularly high numbers. The Site plays also an important role in freshwater supply and shoreline stabilization. Land use is dedicated to tourism, conservation and research. The main threats to the Site are bird disturbance by air force military training and over-exploitation of groundwater.