Margrethe Kog lies right on the Danish-German border by the Outer Dike (Det Fremskudte Dige). It is not a place where you simply walk in everywhere; the experience is especially about the view from the dike and the roads along the polder, where salt marsh, water surfaces, and the Wadden Sea meet in a highly regulated landscape.
For birdwatchers, the site is one of the major locations in Tøndermarsken. Waterbirds, meadow birds, and birds of prey use the area differently throughout the year, and binoculars make sense here because much of the interesting activity takes place at a distance.
Access is clearly restricted: the part south of Vidåen has a no-entry ban, while the smaller northern part north of Højer Kanal/Vidåen has free access. The restriction is not just decoration on a sign, but part of the protection of birdlife.
The marsh trail can be reached from Højer Sluse and follows Højerdiget south along the east side of Margrethe Kog. That stretch is for pedestrians only, so bicycles do not belong on the route itself.
The saltwater lake in Margrethe Kog is man-made. It was created as compensation for nature loss caused by diking, and saltwater is pumped in from the sea to keep the area suitable as a breeding, feeding, and resting place for waterbirds. Nature here is not untouched; it is managed with dikes, sluices, and bird rest as the starting point.
