Zwanenwater en Pettemerduinen is a coastal wetland dominated by humid dune-slacks, marshes, woodland and two connected freshwater lakes, which are among the largest of their kind in Europe. The Ramsar Site name and boundary have been adjusted to the proposed Natura 2000 site. Residential land has been excluded while a natural area in the south has been added, resulting in an increase in the area of 175 hectares. These ecosystems support a rich and vulnerable vegetation as well as endangered species of waterbirds such as the Eurasian bittern Botaurus stellaris, Eurasian spoonbill Platalea leucorodia and lesser white-fronted goose Anser erythropus. The Site is an integral part of the North Sea dunes which protect the Netherlands against the North Sea. Land use is dedicated to tourism, military training, water management, dams, reservoirs and hydro-electric generation. Two birdwatching hides are located at the Site, and a national monitoring programme is coordinated by the Dutch Bird Research Organisation. The military training puts pressure on the ecological character of the Site and causes bird disturbance.