Den Helder dunes
These dunes are formed from the remains of the old Wadden island Huisduinen. South of this are the Donkere Duinen. These originated from the small Wadden island of Ooghduinen. The gap between the two islands closed in the 16th century. The Harmplas dune lake is now located here.
The Donkere Duinen is a planted pine forest that has transformed into a varied, more natural forest. There is a ring-shaped duck pond with bushes along its banks. It can be quite busy in the Donkere Duinen, because it is the only walking forest in the neighbourhood of Den Helder.
The Refugium is a seven-hectare area, which was created by nature development. It lies like a wedge between the buildings of Nieuw Den Helder, the Grafiteitsduinen and the Donkere Duinen. It originated when sports fields were transformed into a new nature area. Now it is really a paradise for special plants.
The Grafelijkheidsduinen and the Refugium are grazed by Scottish Highlanders. Some Konik horses also help in the Grafaliteitsduinen. The grazing in these types of areas ensures varied plant growth. In one place the vegetation is kept short and the soil lean and in places where a lot of fertilizer ends up, plants that love a nutrient-rich soil can grow.