Nature Festival in a vast park in Yvelines

The Fête de la Nature turns 20 in 2026, and the Parc du Peuple de l'herbe in Carrières-sous-Poissy, in the Yvelines (78), marks the occasion in its own way. This Saturday, May 23, 2026, this vast 113-hectare natural space tucked in one of the Seine’s loops between Poissy and Conflans-Sainte-Honorine, opens its doors wide for an afternoon of free guided walks and activities around the Île-de-France biodiversity. Admittedly, the 2026 edition unfolds in a format a little tighter than usual, but the program remains as generous as ever.

What makes this day especially well crafted is the range of offerings. It’s welcoming for families with little ones, for curious teenagers, or for anyone exploring solo with a pair of binoculars and a curious eye. The guided walks, led by expert naturalists and partner associations such as the Ligue pour la protection des oiseaux (LPO) Île-de-France and the Office pour les insectes et leur environnement (Opie), run from 3 p.m. to 6 p.m. in the park. A night-time insect discovery outing rounds out the program for those who want to extend the experience well after sunset.

Meanwhile, the Maison des insectes opens its doors from 2 p.m. to 7 p.m., featuring live insect collections and the current temporary exhibition, produced in partnership with the National Museum of Natural History (MNHN) and the illustration collective The Parisianer. A great opportunity to drop in between two strolls.

To reach the park, it’s about a 20-minute walk from Poissy station, which you can reach from Paris Saint-Lazare. That makes it a perfectly doable car-free day out from Paris or the inner suburb, especially with a Navigo pass. Entrance to the park and all activities are free. Registration for the guided walks is mandatory, either by email at ppdh@yvelines.fr or on-site at the Welcome Desk on the day.

Walks program – Saturday, May 23, 2026, 3:00–6:00 p.m.

Bird courtship in spring

• Led by ornithologist David Rosane
• Departures at 3:00 PM, 4:00 PM and 5:00 PM from the Welcome Desk (in front of the Insect House).
• Registration required: ppdh@yvelines.fr or on site
• Duration: 45 minutes per walk – Suitable for ages 6 and up

Migratory Birds

• Presented by the Ligue pour la protection des oiseaux Île-de-France
• Departures at 3:00 PM, 4:00 PM and 5:00 PM from the Welcome desk
• Registration required: ppdh@yvelines.fr or on-site
• Duration: 45 minutes per outing – suitable for ages 6 and up
• Bring binoculars if possible

On the trail of insects!

• Presented by the Office for Insects and Their Environment (Opie)
• Departures at 3:00 PM, 4:00 PM, and 5:00 PM from the Opie stand (in front of the House of Insects)
• Registration required on-site at the Opie stand
• Duration: 45 minutes per session – suitable for ages 4 and up

Storytelling stroll

• Presented by storyteller Sandrine Rouquet
• Departures at 3:30 PM and 5:00 PM from the Welcome desk
• Registration required: ppdh@yvelines.fr or on-site
• Duration: 1 hour 15 minutes per tour – suitable for ages 5 and up

• To be read
• This week's best bets in Paris and Île-de-France, May 18–24, 2026.
• Free museums in Paris and free monuments in Île-de-France: the top cultural deals

Spotting nocturnal insects (an after-hours excursion)

• Proposed by the Office for Insects and Their Environment (Opie)
• Starting at 9 p.m. in front of the House of Insects
• Registration required: animation@insectes.org
• Duration: 3 hours – suitable for ages 6 and up
• Bring a flashlight and warm clothing.

Outdoor exhibition "Wild Symphony: Biodiversity in Images"

• Presented by the Department of Yvelines
• Along Observatory Avenue, open to the public
• Iconic species of the park with high ecological significance

Schedule at the House of Insects – 2 p.m. to 7 p.m.

Permanent display of live insects

• Presented by Opie
• Live insects on display, a playful, hands-on experience for visitors of all ages

Temporary Exhibition: "The Parisianer, Chronicles of Our Planet"

• Presented by the Department of Yvelines, in partnership with the Muséum national d'Histoire naturelle and the The Parisianer collective
• Large, never-before-seen illustrations at the crossroads of science and fiction, from ancient natural history to distant futures

Spotlight on the artist Hitnes

• Two frescoes on the exterior of the House of Insects, created by Italian illustrator Hitnes, renowned for his biodiversity-focused work

This day is primarily aimed at families with children, nature and biodiversity enthusiasts, the curious who want to learn more about local wildlife, and anyone seeking a free, green outing in Île-de-France within an hour of Paris. For those hoping to stretch the weekend in the area, the Yvelines also offer 50 sorties nature gratuites à la découverte des espaces naturels sensibles en 2026 in their calendar for 2026.

Also read on Sortiraparis

• Parc du Peuple de l’herbe, the Yvelines’ largest nature park, where wildlife and flora meet
• Nature Festival in Paris and Île-de-France 2026: free highlights for the 20th anniversary
• Parks and gardens in Yvelines: the essential green spaces guide for the 78