Les Trois Forêts The history of our “three forests” is in fact linked to the kings and princes of France, but why is that? The Val d’Oise territory boasts a remarkable 4,500-hectare forest that has been state-owned since the Revolution. This forest area includes the forests of Montmorency, L’Isle-Adam and Carnelle, and is mainly made up of oak, chestnut, ash, hornbeam, beech and linden trees. A wide variety of wildlife can be found here, including wild boars, foxes, pheasants, wood pigeons, rabbits and bats. “Les Trois Forêts” have been occupied since Prehistoric times, but it was Philip IV the Fair, a passionate hunter who resided at the Abbey in Maubuisson, who first came here. Jousting contests were also held in the forest, under the reign of Francis 1st, who even attended one in person. In 1526, this King of France gifted the forest to his friend and Constable of France, Anne, Duke of  Montmorency. When the last Montmorency descendant died in 1632, the territory became a fief owned by the Condé family, and then later by the Princes of Conti. These Princes were avid hunters and they had some developments built in the forest of L’Isle-Adam in the 17th century: a surrounding wall was built, 25 km long and 2.70 m high, with a ha-ha to protect the game. Straight alleyways were designed by gardener Le Nôtre, and star-shaped intersections were created for hunters to meet up. At the end of the Middle Ages, most of the forests across L’Ile-de-France were made up of oak trees, but chestnut trees were planted in Montmorency forest, as they were needed to make wooden stakes for the many vineyards in the surrounding area. The wood was also used for the strapping for barrels. At the beginning of the 20th century, people were still living in the forest in huts with their families.

L'Isle-Adam Forest

How do you fancy exploring a 1,548-hectare forest and seeing a linden tree with a circumference of 7.3 m? You can stop your search for these exceptional trees, you’ll find them all here in the L’Isle d’Adam state-owned forest that stretches across 9 towns of the Val d’Oise between the Plaine de France and the Vallée de l’Oise. If you stop off near the Poteau de la Tour intersection, not far from the highest point of the forest (195 m), you’ll see one of the original features of the area. The remains of a three-storey tower, known as Nerville Tower, built for the Princes of Conti so that their guests could watch them hunting. While you’re out on a hiking expedition (25 kms), bike ride (6 kms) or horse-back ride (25 kms), you’ll also come across the Maison Forestière du Bois-Carreau, the many ponds, and you might catch a glimpse of deer, wild boar, foxes or rabbits if you venture down the alleyways designed by gardener Le Nôtre. L’Isle-Adam forest is a popular hunting spot and acts as a green lung where the balance between fauna and flora is respected. Even though the famous 550-year-old great oak tree fell down during the storm of 1999, you’ll see that there is still so much to see in this extraordinary forest.

Montmorency Forest

Did you know that the 5th most visited forest in the region is right here? Montmorency Forest welcomes five million visitors per year.  The forest covers 2,200 ha, 1,972 ha of which is  state-owned forest area (chestnut, beech and maple trees) and is extremely hilly, with very humid low-lying land and three hills at an altitude of 195 m. Several streams leave the forest area and feed into Enghien lake and the river Oise. Cailleuse peatland is also found here, and an ecological inventory revealed numerous remarkable species of beetles and lepidoptera, leading to the preservation of this site. Walkers can use the “sentier des lisières” (27 kms) or the “chemin du philosophe” trails. In the 18th century, Montmorency forest was a favourite place for Jean-Jacques Rousseau to come and walk and collect plants. Some other places to see are the Château de la Chasse, Sainte-Radegonde fountain (the most famous water source of the forest, that is believed to cure infertility), the Pont du Diable bridge, Plumet tower and Godard pond. This pond at the heart of the forest bears the family name of the famous 19th century musician, Benjamin Godard. A trail suitable for people with reduced mobility has also been created.

Carnelle Forest

Carnelle state-owned forest gets its name from the word: “Carn” meaning stone. This forest area has been occupied since Prehistoric times. This 975-hectare forest is on a hill and the top of this hill is one of the highest points of the whole department (210 m). In Carnelle, and in Montmorency, you’ll find the biggest reserve of gypsum in Europe, and this rock has been mined here since 1864. Marl and sand were also extracted here.

The forest is mainly made up of chestnut, beech and oak trees. Several remarkable plant species have been recorded here such as Royal fern. There are numerous species of bird (common buzzard), amphibian (brown frog) and mammals. Visitors can explore along the 30 km of marked footpaths and 21 km of horse-riding trails. It is also possible to enjoy a family picnic here on the shores of the two lakes: The “Lac Bleu” and the “Petit Lac” (swimming is forbidden but fishing is authorised, mainly carp and roach). Don’t leave the Carnelle and Saint-Martin-du-Tertre forest and ponds without exploring the most famous of all the covered alleyways in the region: the “Pierre Turquaise”. This megalithic monument is known as the biggest prehistoric monument in the Île-de-France region.


L'Isle-Adam Parks and Gardens

French writer Honoré de Balzac loved to say that L’Isle-Adam was his “heaven on earth”, and a walk around the town park is enough to see why so many artists found peace and inspiration here. The locals and visitors alike enjoy a dozen green areas throughout the town, and they are managed in such a way as to respect the local wildlife, in partnership with environmental protection associations. Jean Sainteny park is opposite the Garenne ponds. You can come here to relax on a bench or use the wide-open spaces for outdoor games. Cassan park nearby is where you’ll find the iconic “Pavillon Chinois”, the symbolic place of the town. To reach the town centre, it is recommended you walk along the Allée Le Nôtre (pedestrian path), at the end of which you’ll come across Siaram, a creation of Jean Marais. If you walk towards the Oise, you can admire the flowers and temporary open-air exhibitions at “La Roseraie” (rose garden). After Cabouillet bridge, you’ll reach l’Ile de la Cohue across a wooden walkway from the Quai de l’Oise. Here, there are some houses, a shop, a restaurant and a breath-taking view of L’Isle-Adam beach. On the neighbouring Ile du Prieuré, there’s a square where families and small groups like to get together (picnic furniture is not permitted). Throughout its history, this little island has been home to several constructions owned by the town’s noblemen. This is the case for the Château Conti for example, which can also be discovered when the Town Council organises exhibitions there. The relaxing and almost timeless grounds are open to the public, for anyone looking for some peace-and-quiet.

La Rosière Biodiversity Zone

Since 2018, La Rosière has been one of the biggest developed biodiversity zones in the region. This 11-hectare area on the left banks of the Oise is a very pleasant place to visit and it is an ideal habitat for local wildlife. La Rosière is a place of ecological interest and the main goal of the area is to raise awareness with the public about the importance of protecting the environment. This biodiversity zone includes a one-hectare body of water, a grove with 48 trees (Pontoise apple trees, Montmorency cherry trees and Argenteuil fig trees), an enclosed area with a dozen beehives, several spaces with plants and flowers, a pike reserve and some water meadows in the event of flooding from the Oise. 150 shrubs have been planted here, including willow trees and oak trees, and 450 plant varieties (some of them aquatic). 20 species of dragonfly, 30 species of butterfly and 60 species of bird have been recorded across the zone. It is also possible to catch a glimpse of a palmate newt, praying mantis, blue-winged grasshopper or a bat.

CCVO3F Parks and Gardens

Are you dreaming of the peaceful and “zen” atmosphere of Asia? Are you looking to journey across continents without going too far from home? The Municipality Communities of the Vallée de l’Oise and Les Trois Forêts (CCVO3F) can offer this change of scenery! 
In the CCVO3F, there are several green spaces you can explore to your heart’s content. In Méry-sur-Oise, the grounds of the Château, covering an area of 27 hectares are open to the public. The municipality purchased the estate in 2004, and it has been listed a Historic Monument since 1937. This estate was designed as a trail along the water’s edge, taking visitors on a journey to different continents. Behind the Parmain Post Office, there’s a little “zen” park which is strangely positioned on a slope, with some atypical Chinese features and Asian vegetation, with a little red bridge over a stream that flows into a waterfall.


The Etang des Trois Sources

Birds migrating is a fascinating sight. This is a place to discover and to come back to again and again. Migratory birds such as waders flock to this lake, the Etang des Trois Sources. In the north of the town, along the Chemin des Trois Sources, the lake bearing the same name stretches across 1.3 hectares and has a maximum depth of 1.20 m. Around the lake is a park that is very popular with walkers and families. The area has been developed onto a former quarry and there is a wide range of trees here, including poplar trees, and a meadow. An interesting characteristic of the area is that toads come here from the forest opposite, to reproduce (lay eggs). Odonata (dragonflies), fish, ducks, barnacle geese, swans, water hens and coypu have also chosen to take up residence in this natural environment.


Banks of the Oise

The expression “Au fil de l’Oise…” (Along the Oise), is one that evokes wanderlust and makes us feel good. The Oise was formerly known as the “Isara” (tumultuous river in Latin), and it is a river that is bordered by canals and can be sailed along from top to bottom. This river was the very birthplace of 19th-century Impressionism and was a source of inspiration for a number of artists including Vincent Van Gogh (Auvers-sur-Oise) and Camille Pissaro (Pontoise). It runs for 341 km from the Belgian Ardennes to the Yvelines in France and 41 km of the river crosses through the Val d’Oise.
There are cycle paths and towpaths along both banks, reminders of its rich past marked by the shipping industry. The Oise is also dotted with little islands such as Prieuré and Cohue in l’Isle-Adam or Vaux in Méry-sur-Oise. There are some locks in Pontoise and L’Isle-Adam that serve to regulate the regular commercial barges and recreational boats passing through. In these same towns visitors can go on commented cruises down the river during the high season.

The "Etangs" of the Garenne

Did a pair of Egyptian geese really reproduce for the first time in L’Isle-Adam? Yes of course, and it happened in the Garenne district where there are several bodies of water: the Etang du Rarc Sainteny, the Etang des Pêcheurs, the Etang des Vergers and the Etang du Débuché. The fauna here includes ducks, swans, grebes, coots and a number of species of birds choose to nest here. The local plant life flourishes in a harmonious and controlled environment. As an example of this, the “Association des Pêcheurs des Etangs de la Petite Plaine” issued a regulation that only one fish can be caught here per day. There is also a protected passage for ducks, allowing a local resident to feed and care for them.


The Etangs du Moulin Neuf (Presles)

This is a rural area on the edge of Carnelle forest where fish thrive. There is an area for relaxation and leisure activities for the whole family, especially recommended for fans of fishing, looking to catch trout and carp. There are barbecues available for visitors and it is a very pleasant place to enjoy a picnic, under the watchful eye of the geese and ducks.


The Marais de Stors

To quote Arthur Rimbaud, “It is an area of greenery with a river flowing by…”, and it’s obvious why this area is a favourite with poets.  The Marais de Stors is in the town of Mériel, 27 km north of Paris, on the edge of the l’Isle-Adam and l’Oise forests. This classified site in the Vallée de Chauvry has exceptionally beautiful landscapes and forms a mosaic of very sensitive habitats at the bottom of the small valley, crossed by a small stream, the Ru du Vieux Moutiers. Despite its relatively small surface area, this wetland is a remarkable place in Ile-de-France for its rich wildlife.
The 60 hectares of this site are a fantastic hotspot for biodiversity. Between the very dry calcicolous hillside and the very wet peatland, the valley boasts a great number of protected species.

The Lac Bleu and the Petit Lac (Carnelle Forest)

These artificial lakes, with remarkable blue waters, have been developed at the heart of the forest, in former marl quarries, a sedimentary rock that is a combination of calcite and clay. The lakes cover surface areas of 2 hectares and 1.3 hectares respectively, with depths of up to 20 to 30 m. Swimming is forbidden for safety reasons. Fishing is authorised on these lakes.

Photo AeliaFlora

Vexin Français Regional Nature Park

The French Vexin is a vast natural space with some surprising landscapes and habitats for the region: (limestone hillsides, marshland, wooded area, etc. Here, you feel a million miles away and it’s magical!) The Vexin Français Regional Nature Park is in the north-west of Ile-de-France, stretches over 98 towns of the Val d’Oise and the Yvelines and has a surface area of 71,000 hectares.  A special characteristic of the French Vexin is its architectural and built heritage. In contrast with the remarkable architecture of the castles, churches and vast farming estates, is the simplicity of the rural heritage of the French Vexin (cross, windmills, fountains, dovecotes, wash-houses).

The Oise-Pays de France Regional Nature Park

Mother Nature was a great source of inspiration for the Romantics of the 17th century, and it brought about some wild yet charming gardens. You too will be moved by this environment, where Mankind has managed to intervene while respecting the ancient traditions. The Oise-Pays de France Regional Nature Park has been occupied since the Neolithic period, and has inherited a rich historic and cultural heritage with over a hundred classified or listed monuments (castles, museums, religious buildings, troglodyte dwellings). The Regional Nature Park is mainly on the left banks of the Oise and is the link between the Pays de France in the south, and the Plaine de Valois to the east. It is characterised by the presence of three forests (Halatte, Chantilly and Ermenonville) covering almost twenty thousand hectares in total. Stone serves as the geological base and shapes the landscape, while limestone is a source of local wealth. This fertile land is brimming with small farms offering the sale and tasting of farm products. Honey, strawberries, mushrooms, asparagus, eggs, aromatic and medicinal plants, or salted meats are all available here.