The Audomarois Marsh is a vast classified natural area, renowned for its unique biodiversity. Spanning 15,000 hectares, it is the largest marsh in northern France, with a rich ecosystem that is home to a multitude of animal and plant species.
Omer
The site is accessible all year round
Free
Dogs welcome
Facilities
Picnic area
Visitor information available
Disabled parking
Viewpoint
Accessible footpaths
Car parking
Toilets
Geosite details
The Audomarois Marsh is a vast classified natural area, renowned for its unique biodiversity. Spanning 15,000 hectares, it is the largest marsh in northern France, with a rich ecosystem that is home to a multitude of animal and plant species. The formation of the marsh is the result of the meeting between the sea and the Aa River, where sediments have been deposited over the centuries.
The site is also known for its peat mining, which has shaped its landscape and ecosystem. Today, the marsh is classified as a Biosphere Reserve by UNESCO, highlighting its importance for the conservation of biodiversity. Marked trails allow visitors to discover the flora and fauna, while enjoying boat rides in the canals.
The 'Big Bang'
13.8 billion years ago
Earth formed
4.6 billion years ago
540 million years ago
The Cambrian explosion of life: animals evolved and diversified as never before on Earth.
Devonian
419 million years ago
390 million years ago the oldest rocks you can see in the Geopark date back to the Middle Devonian. They are still quarried today in the Marquise basin in France.
Carboniferous
359 million years ago
Around 325 million years ago the Geopark was near the equator. The swamp forests from that period are preserved as coal, which was formerly mined in the Marquise basin in France as well as in East Kent and the Nord-Pas-de-Calais.
Permian
299 million years ago
Triassic
252 million years ago
210 million years ago the Geopark was in the centre of the Pangaea supercontinent, and dinosaurs roamed the land!
Jurassic
201 million years ago
150 million years ago the Geopark was submerged under the sea, the sands, clays, limestones, and sandstones that compose the Boulonnais region in France were deposited.
Cretaceous
145 million years ago
Over about 40 million years from 100-60 million years ago, Chalk formed at the bottom of a warm, shallow sea where the Geopark is located today. This was the first step towards the formation of our distinctive chalk landscape, which defines much of the Geopark.
Palaeogene
66 million years ago
Tectonic activity around 40 million years ago uplifted the territory of the Geopark by dozens of metres, creating an extensive chalk landscape that connected France and Great Britain.
Neogene
23 million years ago
Quaternary
2.6 million years ago
450,000 years ago, a megaflood destroyed the chalk ridge connecting Calais and Dover, creating the iconic white cliffs of the Geopark we see today
