Orienteering, but in reverse
Lots of strands of mixed coloured ribbon or other marker
In groups, decide where to go.
Note down bearing and paces for distance.
At the end of the decided paces put a marker.
Write down the bearing and paces, and secretly right down the ribbon colour or identification of the marker on a seperate sheet.
Then choose where to go next and repeat.
So to build up on orienteering plan.
At the end, plans could be swapped and another group tried to follow the plan and write down ribbon colours they find. Then they can be marked for accuracy.