“Every tree is a lavatory (‘lav-uh-tree’).”
While on my tour around places like Uluru and King’s Canyon, I was constantly reminded by our tour guide that we should visit the toilet every time we had the chance. Sheldon (or “Coffee,” as he liked to be called) would tell us that it could be an hour or more of driving before we’d have another opportunity to visit the loo. At the same time, he reminded us that we always had an alternative.
To be fair, this isn’t terribly different from your common camping experience, but I just thought the way that he expressed the sentiment was creative. You don’t even need a tree, really, since those can be pretty far apart too. Anywhere in “the bush” might have to do… thankfully, I never had to exercise this option.