In the Yvelines (78), about fifty kilometers southwest of Paris, the regional nature reserve of the Étangs de Bonnelles offers a scenic escape into nature, freely accessible and free of charge year-round. Covering roughly 22 hectares of woodlands, ponds, and meadows, the site is part of the Parc naturel régional de la Haute Vallée de Chevreuse and was designated a regional nature reserve in October 2016. Only the northern section, along the two ponds, is open to the public, and that’s where the bulk of the site’s treasures can be found.
The stroll begins gently from the parking lot at the village’s sports center, reachable via the A10 (Dourdan exit, toward Rochefort-en-Yvelines and then Bonnelles). We first walk along Bonnelles’ narrow lanes, passing the moat and the old castle gate, now fully rebuilt and converted into a residence, before crossing the Saint-Symphorien fountain, whose sculpted hands are plaster casts made with the village schoolchildren. A detail that gives the place a distinctive atmosphere, straddling local heritage and collective memory.
The reserve unfolds along the grassy paths: two ponds in succession, the Pond of the Three Dukes and the Chartemps Pond, fringed with reed beds and wet meadows. We move from one to the other by crossing small meulière bridges restored to their original look, and it’s there that you realise why this place feels a touch apart in the Île-de-France natural landscape.
The most striking feature of the site is a two-arched bridge topped by a small building, nicknamed the « temple de l'amour ». It doesn’t resemble the neoclassical columned temples you see at Versailles or Rueil-Malmaison. Here, it’s a more discreet structure, tucked into the greenery, which serves the main island, called the island of the Kiosque. This pont-kiosque is one of the last surviving “fabrics” of the old château park, those small ornamental constructions that were all the rage on 18th‑century aristocratic estates. The best known, the Temple of Love bridge, sits above a watercourse and provides access to an island on which an old landing stage has been converted into an observatoire ornithologique.
This may be where the reserve reveals its true character. The former jetty converted into an observation deck is open to visitors who wish to watch the birds in quiet contemplation. The grey heron, the kingfisher, the honey buzzard, and the Eurasian hobby regularly frequent the pond edges. The site lists 36 species of dragonflies, six of which are protected. The more patient observers might also spot the marsh warbler or the reed bunting in the reeds, two species that nest on site. For those eager to learn more, a discovery booklet published by the Île-de-France region is available at the town hall and at the Regional Natural Park’s welcome desk.
Access to the reserve is free for pedestrians, as long as you stay on the trails. Dogs must be kept on a leash. Entry is from the parking du centre sportif de Bonnelles (sign reading “Réserve Naturelle”), accessible via the A10, exit “Dourdan,” then toward “Rochefort-en-Yvelines” and “Bonnelles.” The route isn’t clearly marked, but discreet wooden signposts highlight the key spots. Nature-focused activities are regularly offered by the Bonnelles Nature association and the Parc naturel régional de la Haute Vallée de Chevreuse.
Our take: A tranquil nature excursion well away from the hustle and bustle of Paris, sure to please both birdwatchers and anyone curious about quirky local heritage. Spring and summer are the best times to watch dragonflies skimming the water and to enjoy the light on the old stone bridges. In this season, violet-hued rhododendrons create a stunning backdrop worth discovering. It’s perfect for a family outing, a romantic escape, or a solo stroll, ideally with a pair of binoculars.
Who is this outing for? For walkers and hikers seeking quiet, unspoiled nature, for lovers of discreet heritage, for families with kids, and for amateur naturalists. No need to be an experienced hiker: the stroll around the ponds is short and accessible to everyone, with no elevation gain.
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This test was conducted as part of a professional invitation. If your experience differs from ours, please let us know.
Dates and Opening Time
From May 9, 2026 to December 31, 2029
Location
The Bonnelles Ponds Nature Reserve
la réserve naturelle des étangs de bonnelles
78830 Bonnelles
Official website
www.parc-naturel-chevreuse.fr
