everyone's eyes are closed. The 10 children are sitting quietly, listening as a stream sloshes its way over moss-covered rocks and a breeze murmurs through nearby trees.
After a minute, the P5 pupils from Roslin Primary are told they can open their eyes. Eoin Keane asks them to describe what they have heard. There are a few moments of debate about swishing, swirling, mumbling and grumbling, then the backpacks go back on and the children set off towards the "swamp" they have been looking forward to negotiating.
Mr Keane is a 30-year-old teacher whose classroom is vast, ever-changing and likely to give you a good soaking from time to time: Scotland's great outdoors. He is one of about a dozen outdoor learning teachers registered by the General Teaching Council for Scotland. To spend a day observing him at work is to realise that outdoor learning means far more than having a bit of fun with a kayak or an abseiling rope.
One day last month with the Roslin pupils, Mr Keane covered aspects of traditional subjects such as English, geography, maths, biology, history, and topical areas such as healthy eating and the environment.
Based at Midlothian Council's outdoor learning centre at Gorebridge, he works with hundreds of pupils from nearby primary and secondary schools. He brings a passion for the outdoors but, as a teacher, also a close working knowledge of what is being covered back at school.
The day with the Roslin P5s starts with an indoor briefing on safety, although learning, too, is already taking place. The children are shown a satellite image of Vogrie Country Park, where they will spend the day; a few hours later, they will walk past the same buildings, paths and streams, gaining a sense of how an aerial view relates to three-dimensional perception of one's environment.
The opportunities to learn come thick and fast once out in the open. Mr Keane stops by some snowdrops - evidence, he explains that the nights are getting longer and days are getting warmer. Nearby, the group edges up to a pond to peer towards a thick band of gluey frogspawn. Mr Keane talks about the life cycle from spawn to fully grown frogs seeking to create their own offspring. He conveys ideas with the articulate enthusiasm of a children's writer, as in his vivid account of mating frogs: "The boys croak as loudly as they can or wrestle to win the girl's heart."
Next comes a look round a "sensory garden", where the children can smell rosemary while wind chimes tinkle in the background.
Mr Keane constantly asks questions: What can you hear? What does that smell like? Where have you seen that before?
Each child has a map. Mr Keane explains what a map is and introduces the idea of scale. It is a picture, he says, only from a certain point of view, and points out an impressive walled garden that appears as a modest rectangle on the map. He flips over his map to reveal a drawing of a face, which he turns upside down. In the same way, he explains, a map can be held the wrong way round, making navigation as difficult as reading a book upside down. But, unlike a book, the right way up changes depending on which way the map-reader is facing; if you do not rotate the map, you may have to walk backwards all day.
This takes place before the main part of the day, a walk round the park, has begun. The group is led by a child and brought up at the rear by another, the "sweeper". Every pupil gets a chance to perform these roles, taking responsibility for the safety of others and making sure no one is struggling to keep up.
The walk is broken up with physical activities that might seem like more traditional features of outdoor learning. The group trudge through a sodden stretch of land and clamber along a footbridge, before ducking down and easing their way underneath, taking care not to slip in the stream that it straddles.
"No one's going to make fun of you," says Mr Keane, as he reassures anyone who might be anxious. "If you don't like doing something, that's OK - people have different strengths in different areas."
Carolyn Cockram, a learning assistant at Roslin Primary, believes the children are getting benefits that cannot be easily provided in school.
"It's an opportunity to get out and about," she says. "Kids these days don't do enough of this. They learn a lot of things they don't see in schools. We do see a different side to them. Their personalities come out.
With kids that are quiet or don't shine academically, something like this can really bring about a change."
Chalmers Smith, an outdoor learning co-ordinator who works with Mr Keane, agrees: "There are things that happen in outdoor learning that don't happen anywhere else. In terms of personal and social education, children are finding out about themselves and other people in a different setting."
Outdoor learning in Midlothian appears to be having an impact in the home, he says, with parents reporting that they are being inspired to get outside - all Midlothian's outdoor learning takes place locally so children can revisit places in their own time. "In a society that's often exam-based and test-based, it's quite healthy to think that parents are valuing this,"
says Mr Smith.
A Curriculum for Excellence brings hopes of a new dawn for outdoor learning in Scotland. Since its heyday in the 1970s and 1980s, it has become increasingly marginalised, with the 1996 reorganisation of local government bringing about the loss of many experienced practitioners.
But curricular flexibility is now expanding concepts of what teaching might entail, to the benefit of marginalised areas such as outdoor learning. Mr Keane talks enthusiastically about A Curriculum for Excellence, which he sees as a big potential boost for his subject. Outdoor learning, he believes, is far more than an entertaining diversion from the serious learning that goes on in the classroom. It complements classroom-based learning and - in some cases - exceeds what can be achieved back at school.
"The fact that children are having the experience of what they are being taught about makes it more real and tangible," says Mr Keane. "That might be more difficult to achieve in the classroom."
Eoin Keane will assist Hazel Williamson, of the Youth Sports Trust, in delivering a seminar on Top Outdoors - a training scheme that shows how outdoor learning can be done on school grounds - at the Scottish Outdoor Learning Festival in Edinburgh's Royal Highland Centre at Ingliston on Monday
Outdoor learning is already central to how children are taught in Scotland -until they get to school. That is the view of David Cameron, chair of the Outdoor Learning Advisory Board, who believes "a lot of the key, critical work in early years" could be termed outdoor learning.
This, he says, shows that playgrounds can be used for outdoor learning in the same way as forests and country parks.
Mr Cameron, director of children's services at Stirling Council, witnesses good outdoor learning work "virtually every time" he sees early years education: "I see young people outside, learning about space, learning about themselves."
All that changes at school, however, where children are wedded to more traditional curricular concerns. "We need to reflect on why we have got so much activity at this stage and why that tends to tail off," he says. "Some of it is to do with the pressures of the curriculum and, hopefully, A Curriculum for Excellence will bring flexibility and space that will allow educators to look for high-quality learning experiences in a variety of environments.
He points to the "huge success" of initiatives such as Eco Schools, underlining that Scotland has a "very reflective profession" that is open to new ideas.
Mr Cameron says one hurdle is the fear of the implications if a child is hurt during outdoor activities. "There is a sense of caution about risk, but we tend to highlight those few instances where things go wrong, rather than the considerable ones where things go right."
Mr Cameron does not believe there will be barriers to outdoor learning from people who do not consider it "proper" education. "I would hope we are getting beyond that stage," he says. "There will be some people with a traditional view of what education and learning should be. But there are also a lot with a traditional view who would see that the outdoors is very much part of education."
David Cameron will deliver a speech at the Scottish Outdoor Learning Festival on Monday