The nature of the dunes The hundreds of dunes of the Waterleidingduinen filter rainwater, the first step in the process of creating fresh drinking water for the city’s residents. It’s a great place for a walk, run or hike, but bicycles aren’t allowed in –helping to protect the dune landscape. Instead, a dedicated cycle path connects the park to the coastline. It’s not uncommon to see wild foxes romping through the underbrush and deer grazing in the dunes. And there’s naturally also plenty of plant life: the Amsterdamse Waterleidingduinen are also home to the largest array of toadstools and mushrooms in the Netherlands.