Thousands of teenagers from across the region have set off on the annual Ten Tors event.
School children are pacing Dartmoor on an expedition they have been training for for months.
They will be navigating across 35, 45 or 55 miles of moorland carrying their own food, water and shelter across the terrain by themselves.
There is no help from adults on their journey, the 14-19 year olds in teams of six, will return to base tomorrow morning.
Taking part in the Jubilee Challenge are children with physical or educational needs who tackle routes of up to 15 miles cross country.
Track the participants by clicking here.