Réserve naturelle régionale du marais de Stors, Regional nature reserve in Mériel, France

The réserve naturelle régionale du marais de Stors is a 47-hectare regional nature reserve in Mériel, Val-d'Oise, classified in 2009 and managed by the Agence des espaces verts de la région d'Île-de-France. It lies in the Chauvry valley, where tall grasses, sedges and leafy plants grow among pale pinkish-white flower clusters beneath a canopy of trees.

In the 12th century, monks from the nearby Notre-Dame du Val abbey used the area for fish farming, shaping the land and its waterways in ways that are still visible today. Parts of the marsh were later drained in the early 20th century to create farmland, then abandoned in the 1970s and officially protected as a regional nature reserve in 2009.

The reserve lies in the Chauvry valley, on the land of Mériel in the Val-d'Oise. It has been managed since its creation by the Agence des espaces verts de la région d'Île-de-France, the regional green-space agency. The name Stors refers to the marsh itself, and the site is classed as regional nature reserve RNR204.

The reserve is accessible from Mériel, where marked trails lead through the site without disturbing the fragile habitats. Visitors are expected to stay on the signposted paths, and wearing sturdy shoes is a good idea given the wet ground in many areas.

The reserve covers 47 hectares in the Chauvry valley, on the land of Mériel in the Val-d'Oise. It was classified by a deliberation of 9 July 2009, and a deliberation of 21 November 2012 set out the precise list of parcels concerned. The Agence des espaces verts de la région d'Île-de-France manages the site.