By Mark Mardell
BBC Europe editor, Rospuda, Poland
There is the occasional twitter of birdsong, the gentle splash of paddles, the brushing past of the reeds. All the rest is silence.
Canoeing is one of the attractions of the unique wetlands
The waters are extraordinarily clear, and you can stare down several feet to watch the fish dart around the river bottom. A swan hisses as we pass. It is a very peaceful experience canoeing down the Rospuda River in north-east Poland.
But environmental campaigners warn it could soon be desecrated by diggers and bulldozers, by the huge legs of a motorway bridge. Then its clear waters will be muddied with the pollution of thousands of vehicles a day thundering overhead.
The campaigners hope a European Court ruling in early September will follow the strong lead given by the European Commission and instruct the Polish government to officially stop work on a planned bypass around the town of Augustow.
A full judgement would then follow in perhaps a couple of years. The motorway either side of this area is still being built but work on the bypass, due to begin on 1 August, has been put on hold.
The area is not just beautiful and serene. It is covered by the Natura 2000 European directive, intended to protect wildlife and wild habitats.
The Polish Society for the Protection of Birds (OTOP) says the area is home to two types of rare eagles as well as buzzards, kingfishers and other rare species.
In the nearby Augustow Forest about 36 wolves roam wild, along with elk and lynx. There are rare plants including several types of orchid. Environmentalists also claim that the land itself is unique, perhaps the last pristine example of peat bog in Europe.
The wetlands are home to abundant wildlife including rare species
Malgorzata Znaniecka from OTOP shows me where the motorway would be built, a bend in the river, just before it runs into the wetlands.
Green campaigners want the bypass to go much further to the west, and propose a longer road, which does go through the Rospuda Valley, but not, they say, through any area of special interest. A mile or so away from the proposed site is the bog itself.
"It's like a big lake filled with peat," says Ms Znaniecka.
"Because this is very well preserved and there hasn't been much human activity it's the perfect home to many animal and plant species. The road would create a barrier to migration, it would make a lot of noise, chemical pollution.
"We would lose a special place for people. There is a lot of tourism, guides, canoes - I think it would be much better to preserve it and be proud of such a site, rather than just have a road. We have a lot of roads everywhere."
She says the EU has made all the difference.
The support from the European Commission is "much stronger than we had before from the Polish authorities," she says, confident that Brussels' protection will extend to other areas threatened by the same road, the Via Baltica.
But this is not a simple case. Poland has few motorways and the roads are narrow, slow and dangerous.
With thousands of lorries and the occasional tractor chugging along the two lanes linking most cities and towns, frustrated motorists take their lives in their hands, hitting the accelerator hard and pulling out suddenly to hurtle past lines of trucks that clog the roads.
Cars in the opposite direction pull over onto a sort of half hard-shoulder, that sometimes runs alongside the road itself. Sometimes it doesn't. Mostly the drivers make it. But there can be no doubt that more dual carriageways would mean fewer deaths and injuries.
Residents of the pretty little spa town of Augustow are at the heart of the Rospuda dispute.
Augustow - a pretty spa town - is blighted by heavy goods traffic
Many here make their living from tourism. For years they have been campaigning for a bypass, sometimes blocking all traffic with their day-long protests.
The town of about 3,000 is on Europe's main east-west route. Lorries from the Baltic countries and Russia thunder through here, past the pretty canal and quaint wooden houses.
I watch a young couple walking with their toddler and pushchair a few hundred yards from the canal to a roundabout in the town centre. In the few minutes it takes them six lorries whistle by. The average on this roundabout is four a minute.
The headmaster of the town's main school, Bogdan Dyjuk, leads the campaign for a bypass. He points proudly to a sign by the roundabout - "one of ours", he says. It reads, in English: "I am part of the protected area nature 2000: I am demanding protection! - A Human".
He says traffic has increased dramatically since Poland and other eastern countries joined the EU in 2004.
"The number of cars going through the main border crossing has increased from 3,500 to 5,800 a day.
"In 2004-5 there was a 40% increase in traffic, then in 2005-6 another 38%. And they all go through Augustow. We've got used to sneaking onto the zebra crossing between the lorries, fearing for our lives, mastering the art of using our cars to use every single space between the trucks to get around the town."
He says the town's canal was built in 14 years in the 19th Century, "but we've been discussing the design of this road for 15 years". He argues that with forests and lakes on all sides "there is no way of avoiding going through the natural environment".
He is not happy with the EU's role in all this.
"Can you imagine if in the UK, when you were about to join the EU, you had some investment ready to go, and it was blocked and thrown into a dustbin? Unthinkable. If we base our decision on the EU laws it's going to take another 11 years to get this road.
"We don't accept Europe trying to preserve the status quo here: soon they will want us to wear traditional peasant dress and drive a horse and cart."
Augustow's mayor Leszek Cieslik has been embroiled in this battle for years and seems to care deeply about getting the balance right between the needs of his town and the environment.
He insists the planners have taken care to minimise environmental damage.
The bridge is longer and higher than it needs be, the supports taking up only a tiny area of the valley, he argues.
He, like many in the town, thinks deep European politics is at play. Mr Cieslik says in particular Polish opposition to a pipeline from Russia through the Baltic has annoyed other countries.
It is true that many in the EU assume the Polish objection, on the environmental grounds, is a cynical ploy, a shield for the true political objection and wariness towards their old masters, the Russians.
"They're saying: 'if you're so worried about the environment, look how you are prepared to damage it yourself'. They're looking for little hooks to catch Poland, to show who is the ruler," says Mr Cieslik.
After consultation at the European level, "it should be up to the state or the local communities to decide what they want," he says.
He adds that when Poland joined the EU most of the town was in favour. He doubts that would be the case now.
"The European Commission sees ecology as a religion, even though they don't like religion much. It's not a religion, it's science."
Certainly some Poles are having real doubts about the EU - perhaps not about the decision to join, but the treatment they have received since, from French fears of job-seeking Polish plumbers to the European Parliament hostility to their government's hardline social conservatism. This case will make them all the more sceptical.
But others see the EU as a force for modernisation and protection. Back in the valley Malgorzata is hopeful that European rulings will preserve an area she adores.
"We are part of the European Union and this nature is protected by EU law. We decided to enter this club so we are obliged to follow its rules. This is not only Polish heritage, it's heritage for all of Europe."
The row, like the traffic through Augustow, will probably rumble on for many months, if not years.