Eight of them are crashing through the undergrowth, racing across the grass, ducking under branches. "I'm wrecked," says Jennifer Ward, s first-year from the Christian Brothers' School in Dublin's Westland Row. Her class has gone native - they're like the Tuatha Dee Danann on a berry gathering expedition.The eight pupils and two teachers are on a treasure hunt on the shores of Glendalough's upper lake in the heart of the Wicklow Mountains National Park. "The treasure hunt was brilliant and they're actually learning as well, " says teacher Eddie Kelly, his chest heaving as he tries to catch his breath. Lyndsey Mullen, another first-year, runs up, convinced she's got the final answer to the treasure hunt riddle.Holding onto their maps, the group gathers round to hear the next activity which has been planned for them by Sue O'Callaghan and Hugh McLindon, their park guides for the day. They hop with excitement. It's cold and grey, but the morning is going well and their designer trainers are bearing up under all this outdoor stuff."You become a kid again," says Callaghan, as she looks at her young charges. "I love this work," she says, handing out a number of magnifying glasses and collecting the maps. They're about to go off looking for particular leaves and insects.Raymond Stephens, the national park guide with responsibility for the education programme, looks as if he 'd like to join them on the next part of the trek but he has to entertain a wide-eyed reporter. These tours are available to school groups, free of charge, throughout the year."We have to focus their energy," he says. "You have to focus them all on one thing, you might find a burrow or a birds nest. Some need to be excited and inspired. Some are wired to the moon and want to leg it up to the top of the mountain."There are lots of props, Stephen explains, as he rummages on a shelf packed with compasses, trays, rulers, quadrants and various kinds of glass recepticles.Last year just under 5,500 young people from all around Dublin and surrounding counties took part in the park's education programme, which is funded by Duchas, the Heritage Service, under the Department of Arts, Culture, Heritage and the Islands. Children as young as four years of age, lots of 12-year-olds as well as Leaving Cert students and university groups have availed of the park's service. There have also been groups of physically disabled and mentally disabled youngsters.The programme aims to promote understanding, respect and care for the natural world. It works to encourage people to have a harmonious relationship with the earth and to teach people about the National Parks and Wildlife Service and its role in conservation.It's all very orderly, then? Stephens smiles wryly as he recounts some of the unplanned antics which youngsters can get up to if they're let off on their own. "They just want to fling themselves into the lake. They're just magnetically attracted to water...we're very strong on safety. It has to be a major consideration. You have to be goods with children. From a safety point of view you have to be able to control it Usually we would take up to 15 in a group - we'd be generally able to cope with that number."Each group is taken by two park guises, with two teachers or parents tagging along also, on a kind of voyage of discovery, each trip with its own list of activities.Nature awaits in this lovely part of Wicklow - mushrooms, frog-spawn, badgers' sets and rocks of every description at every turn.Schools interested in afield trip should contact the education department of the Wicklow Mountains National Park - phone (01) 40445338, fax (01) 40445306.