Pupils from the eight secondary schools in Angus were put through their paces by member of Royal Marines.
Youngsters faced a series of physical challenges set by members of the elite force around RM Condor base in Arbroath.
The event was the fourth Spirit of Adventure day to be held in Angus, which aims to introduce children to new experiences.
Pupils were welcomed to the event by Angus Lord Lieutenant Mrs Georgiana Osborne and the Commanding Officer of 45 Commando, Lt Col Dan Cheesman.
Mrs Osborne said: “The aim of the Spirit of Adventure day is to give the young people involved the opportunity to take part in challenging activities and push themselves in ways outside of the school environment.
“Today they are being faced with a series of activities they may never have done before and I know it will be an exciting experience. If anyone knows about challenges it is the Royal Marines.
“I am so grateful to Lieutenant Colonel Cheesman for laying on this day and providing so many of his men to put the children through their paces.”
Lunch was served to the pupils in a field kitchen set up under Condor’s dry ski slope.
On completion of the day’s activities, eight youngsters were awarded a six-day adventure holiday at the Ridgway Adventure Centre at Ardmore in the Highlands.
Mr Cheesman said: “Some of the youngsters might be challenged a bit by the activities, but that’s what life is all about – embracing the challenge and pushing themselves a little bit further.”
He told the children that he had a personal connection to the Ridgway Adventure Centre as he was an instructor there when he was 18.
“It’s a fabulous place, a challenge that will stretch you and you will do things you’ll never do again and you will never forget it,” he added.
The first Spirit of Adventure day was held as part of the Queen’s Diamond Jubilee celebrations in 2012 when youngsters completed six different walks through Glen Clova and Glen Prosen.