National and natural reserve of the Romelaëre ponds in Clairmarais (7)The National Nature Reserve of the Romelaëre ponds originates from ancient peat bogs whose exploitation, mainly in the 19th century, gave birth to the different water bodies of the site. The Romelaëre is a space of about a hundred hectares dedicated to the conservation of biodiversity and to the reception of the public, including people with reduced mobility thanks to a path of almost 2 km. It is also the starting point for many hiking trails. THE BLONGIOS(7)
©Walkers in the national and natural reserve of the Romelaëre ponds in Clairmarais|Eden 62
A concentrate of nature

The Romelaëre Reserve

I have been told that this is one of the most beautiful places in the Pas-de-Calais to admire nature. In Clairmarais, a stone’s throw from the town of Saint-Omer, the Romelaëre Nature Reserve is one of those little corners of paradise that make you want to protect the environment. Here, I discovered treasures by observing the inhabitants of these protected landscapes.

A not so natural reserve

“These ponds are not natural,” Eden 62 guide Jean-Denis Ratier explains to me at the entrance to the site. Not natural? But where do all these bodies of water come from, which occupy 45 hectares of the 104 hectares on which the Reserve extends? This fuel was used for heating”, explains Jean-Denis. Hunting reserve, leisure base, the places are classified National Nature Reserve in 2008.

They are discovered along 3 very accessible paths. Let’s explore, along the 4 km of the Cormorant Trail, along a pleasant path on stilts.

"Enjoy a lesson in botany"

Paradoxically, this wetland requires constant maintenance “so that the environment does not close and become a forest again,” explains our guide. I won’t go into an inventory à la Prévert. If you like numbers, the box below is made for that. But I’m enjoying listening to the stories of the carnivorous bladderwort, the aquatic Cigüe, and the marsh chickweed.

Or watching the colors of the orchids. And what a diversity of landscapes! Sometimes I feel like I’m in a reedbed in the Pays de la Loire, sometimes in a small Camargue. “The site is part of the world network of Ramsar wetlands, essential to the balance of the planet. The amount of biomass approaches that of an equatorial forest ” says Jean-Denis.

"Meet a Noah's Ark

“Here, it’s like a surprise package, you never know what you’ll run into,” Jean-Denis laughs. I stop to listen to the reed warbler singing. Further on, it is a crested grebe chick that can be heard. Here is a tern, a sea swallow, and a little further, great luck, we will see a starry Bittern, emblematic bird of the reedbeds. In the middle of the walk, an observatory offers me a direct view on one of the largest colonies of cormorants in France. European kingfisher, jackdaws, ducks of all kinds: the Nature Reserve is an immense open-air aviary for 230 species of birds, including many migratory ones. “Not to mention the fish and insects,” completes Jean-Denis, stopping to photograph a magnificent Machaon.

Understand to protect

Yet, even here, nature is threatened. Climate change, the impact of human activities, urbanization: the Little Bittern, the symbol of the Parc naturel des Caps et Marais d’Opale has disappeared from the scene. We see less swallows and we no longer hear the cuckoo. So if I had to retain two things from the visit of this exceptional site, it is at the same time the beauty and the fragility of nature. And the need to protect this exceptional heritage. So go on with your discovery! The Nature Barn, just next door, will perfectly complete your stroll.

Some figures

3 paths

Cormorant Trail (4 km), Blongios Trail (2.7 km), Nieurlet Trail


104 ha including 45 ha of ponds, 22 ha of reedbeds and megaforests, 22 ha of wet meadows and 5 ha of peat woods.


240 notable bird species, 17 different fish species and 70 species of beetles and 70 species of butterflies