I agree that what you teach should be meaningful and usable.
There's a good outdoor learning activity on http://www.montanalingua.com/fileadmin/ ... nsBuff.pdf
called "Blindman's Buff" - which BTW is completely different from the original blindman's buff - two students take responsibility for a third blindfolded student and lead him/her through a mild obstacle course. Language content of this lesson includes nouns such as "branch, slope", adjectives such as "steep, slippery" and instructions such as "keep going, duck".
As it says on the Montanalingua website: "It is essential to use the target language to succeed in each challenge, and therefore it gives motivation to learn to be able to take on further challenges."
Hope this helps!