The spring kicks off a wonderful nature season in the Yvelines! Starting April 4, 2026, the Department of Yvelines relaunches its annual program of 50 free nature outings across its Espaces Naturels Sensibles (ENS), those vast protected areas that make this department the greenest in Île-de-France. Lace up your walking shoes and let's go!
With 70,000 hectares of woodlands and forests and 85% natural and agricultural areas, the Yvelines offer a remarkable natural setting, shaped by valleys, ponds, and sweeping rural plains. In total, 2 880 hectares of natural spaces managed and developed by the Department are open to the public year-round, from the forests of Rochefort-en-Yvelines to Sainte-Apolline in Plaisir, via the forests of Grands Bois, Flambertins, and Madeleine in Chevreuse.
This year 2026, the program’s guiding thread is clearly aquatic: the outings invite you to explore wetlands in all their forms. Ponds, small lakes, streams and wetlands become the perfect playground to meet frogs and toads, watch dragonflies skim by, or try to spot the famous kingfisher diving for its prey. A “waterway” theme that runs through much of the program and gives real coherence to this edition.
Beyond the nature-and-water thread, the program also offers a range of themes to suit everyone’s tastes: santé et bien-être—translated here as health and well-being (sensory walks, forest yoga, Nordic walking, an Indian-inspired walk drawn from Navajo traditions)—, découverte de la faune et de la flore—wildlife and flora discovery (birds, insects, mushrooms, remarkable trees)—, sport-nature—nature sports (archery, disc golf, orienteering, fun archery)—, and even art-nature—nature-inspired art (land art, trunk sketches, forest storytelling).
Among the can't-miss spring events, there’s the nocturnal outing “La chorale des anoures” on the evening of April 10 in the Flambertins forest with the association La SEVE, a sound immersion by the edge of a wetland to listen to frogs and toads singing after dark. We also like the idea of a photo outing with wildlife photographer Nicolas Dubois on April 12 in the Ronqueux forest in Bullion, to learn how to read the tracks left by wild animals. On the birds front, the Ligue pour la Protection des Oiseaux (LPO) is partnering with several spring outings, including a session listening to migratory birds on April 22 at the departmental site Bout du Monde in Épône, and a walk focused on songbirds in the Méridon forest. For families, the naturalist treasure hunt on May 9 in the Flambertins forest blends strolling, observation and the creation of land art in a playful way.
On the insect front, the OPIE (Office pour les insectes et leur environnement), a Guyancourt-based association in Yvelines and the national reference on entomology, runs several field workshops throughout the program: discovering small aquatic creatures, observing dragonflies in summer, and exploring the world of forest insects. A great opportunity to change the way we view these often little-known creatures.
Summer isn’t being left out: in June, the program joins the festival Nuits des Forêts (June 5–21, 2026), an annual gathering that forges links between art and ecology and invites citizens, artists, and foresters to share powerful, immersive moments in nature, by day and by night. In Yvelines, twilight outings let you hear the owl hoot, watch bats, or witness the roaming performance “Ecorcés” in the Sainte-Apolline forest—a poetic experience at the heart of the trees. In July and beyond, the outings continue through November, with the deer rut in September or the discovery of mushrooms in autumn.
These outings warmly welcome both families with children (most start at age 6 and up) and nature lovers, whether exploring solo or in a group. For people with reduced mobility, several outings are adapted accordingly, such as the May 6 stroll in the Flambertins forest, where the pond sits roughly fifty meters from the parking area.
All outings are free, but registration is required to ensure you’re welcomed in the best possible conditions. To sign up, head to the free ticketing site. The complete guide to the 50 outings of 2026 is available online at Calameo. For any questions about a particular activity, the team can be reached at animationens@yvelines.fr. Be sure to bring sturdy walking shoes, weather-appropriate clothing, water, and a snack for longer outings. In addition to guided animations, some sites also offer self-guided routes via the free app Balade Branchée or downloadable activity booklets.
Do you love nature walks in Île-de-France? The National Nature Reserve of the Yveline ponds and ditches, a legacy of the Sun King’s hydraulic network, offers its own guided tours around the Saint-Quentin, Perray, and Saint-Hubert ponds. The Parc départemental du Peuple de l’Herbe in Carrières-sous-Poissy is another go-to for year-round activities, especially with the Maison des Insectes of OPIE open to the public on site. And to explore other sensitive natural spaces on your own, Destination Yvelines lists all the sites and trails available in the department.
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Dates and Opening Time
From April 4, 2026 to November 29, 2026
Location
Yvelines
yvelines
Route planner
Prices
Free
