Buitenlanden Langenholte is a protected floodplain nature reserve north of Zwolle, in the area where the Vecht and the Zwarte Water rivers come together. It is a wet, rough, and highly dynamic landscape shaped by the river, with open meadows, marshy vegetation, and rich wildlife. The reserve is especially famous for its vast fields of wild snake’s head fritillaries, making it one of the largest natural sites for this flower in Europe. (Landschap Overijssel)

Because of its exceptional ecological value, Buitenlanden Langenholte is designated as a Natura 2000 site. The area supports many vulnerable species, including meadow birds, rare plants such as golden buttercup, ragged robin, great burnet, pink Dianthus, and yellow bedstraw, as well as fish species like weatherfish, tench, burbot, and bitterling. Conservation work in the reserve focuses on protecting the fritillary meadows and restoring habitats that are under pressure from agriculture, industry, and traffic. 

The reserve is not freely accessible because of its fragility, but part of it can be viewed from the dike and cycle path nearby, and it can also be experienced from the water by boat or canoe. Since 2021, restoration measures have been carried out to improve biodiversity and strengthen the natural quality of the area. 

This project is part of the Locus Sonus Soundmap, a worldwide network of open microphones that continuously stream local soundscapes online. In the wetlands near Zwolle, a microphone broadcasts the area’s sounds 24/7, allowing listeners to hear birds, wind, water, and other environmental sounds in real time. A BirdWeather PUC simultaneously analyzes the live audio and helps identify bird species as they are detected. A security camera is also installed on site to monitor possible intruders. The project brings together nature, technology, and listening in a continuous live composition.