Wieden and the adjoining Weerribben (Ramsar Site no.193) form the largest peat swamp of its kind in Western Europe. The Site is characterized by shallow freshwater lakes, reed beds, fens, wet meadows, transition mires, quaking bogs, forested peatland and numerous canals created through peat extraction activities which took place until the 1920s. The boundary was adjusted to match that of the Natura 2000 Site in 2017; some wetlands were included while some agricultural land, residential and recreational areas were excluded. The Site regularly supports more than 20,000 wintering waterbirds and is a refuge for more than 1% of the European populations of the greater white-fronted goose (Anser albifrons). It also supports notable species of plants, fish and butterflies. The European otter was reintroduced in 2002. The lakes act as water storage reservoirs during the summer and provide water for irrigation. Human activities relate to tourism, angling, boating, commercial fisheries, farming and reed harvesting. The main threats to the Site derive from water abstraction for farming, drainage and pollution. There is a visitors’ centre, and biodiversity monitoring activities are carried out by the Dutch Bird Research Organisation.