A compilation of most of the seminars presented during a symposium held in Arnhem, the Netherlands. The introduction treats not only the Netherlands as wetland in a larger landscape but also the various wetland types within the country itself. The subsequent case studies concern representative wetland types. Both introduction and case studies give an historical, hydrological, physicochemical and biotic characterization of the wetland concerned, as well as a description of management measures in the past and in the present; summarize the threats to the systems; and indicate prospects for the ecosystems, given the present environmental conditions and expectations for short- and long-term changes. In the introduction, special attention is paid to the border-crossing biotic elements, such as birds. These sections are followed by a summary of the ecology of the Netherlands’ wetlands and indications for future ecological research. Finally, the environmental policy and its consequences for management on a national, regional and local scale are discussed.