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Students from Sheldon School near Chippenham have been preparing for five months, doing long walks and doing a trial weekend in Wales.

The teams must carry everything they need to complete the route and stay out overnight safely.

They will tackle Dartmoor's rough terrain on hikes of 35, 45 or 55 miles, depending on the age of the team members.

They must visit the ten tors (checkpoints) in under two days.