Etang Neuf

Étang Neuf is a small forest pond in the commune of Gambaiseuil, in the Yvelines department, tucked deep within the Rambouillet State Forest. Sitting at roughly 115 metres above sea level, it covers an area of about 3 hectares and is bordered on its western side by an artificial dike that gives the pond its distinctive elongated shape.

Where exactly is Étang Neuf located?

The pond lies at the heart of the Rambouillet forest, south of the village centre of Gambaiseuil. It is one of many ponds scattered across this extensive woodland, which has served as a water reservoir system for the surrounding countryside for centuries. On its southern edge, Étang Neuf connects to a hydrological chain that runs upstream through Étang Rompu to the Hollande ponds, and downstream via the Grapelin stream to the Vesgre river. This means the pond is not an isolated body of water but part of a wider drainage network that shapes the whole forest.

Why is this spot ecologically important?

The area surrounding the pond forms part of a zone officially classified as a Type 1 Natural Area of Ecological, Faunistic and Floristic Interest (ZNIEFF), named "Valley of the Ponts Quentin stream from Grand Baliveaux to Étang Neuf," which covers 436 hectares in total. It is here that nationally protected marsh ferns and other rare wetland plants grow, thriving in the damp, shaded microclimate around the water. Reed beds and shoreline thickets are also home to kingfishers, which can be spotted darting low over the surface in search of small fish.

What can visitors do at Étang Neuf?

The pond is a well-known feature on walking routes that start from the car park near the Sainte-Croix church in Gambaiseuil. A circular forest trail passes close to the biological reserve of Grand Étang Neuf, combining a walk beside the water with a route through the dense, fern-covered undergrowth typical of this part of Yvelines. The loop covers around 9.2 km and takes an average of 2 hours and 20 minutes to complete — a manageable distance for a day outing that suits walkers of varying experience levels. The trail also forms the fourth stage of the GR22, a long-distance hiking route connecting Paris to Mont-Saint-Michel, making Étang Neuf a recognisable waypoint for hikers tackling that longer journey.

What does the landscape around the pond look like?

The surroundings are typical of the Rambouillet forest: thick fern undergrowth, damp hollows in the terrain, and paths winding between broadleaf trees. The quiet atmosphere of this part of the forest, combined with the presence of water, draws visitors looking for a peaceful walk and a chance to observe wildlife away from the busier trails closer to the town of Rambouillet itself.

Frequently asked questions

Can you swim in Étang Neuf? Available sources give no indication that the pond is set up for swimming — it functions primarily as a protected natural area and a destination for walking trails.

How do you get to Étang Neuf? Most visitors start from the car park near the Sainte-Croix church in Gambaiseuil, from where forest paths lead toward the pond.

Are there any rare species around the pond? Yes — the area is protected as a Type 1 ZNIEFF due to its nationally protected marsh ferns and other rare wetland plants, as well as the presence of kingfishers.

Is the trail around the pond part of a longer route? Yes, the section passing Étang Neuf forms part of the fourth stage of the GR22, a multi-day hiking trail running from Paris to Mont-Saint-Michel.