One of my favorite things to do when traveling through remote parts of the world is to pop into a local classroom. At the very least, it usually leads to a few laughs. Sometimes it becomes a meaningful exchange of cultures, common language or not.

In 2002, while walking through a small village outside Bujumbura, Burundi, I came across an elementary school and was welcomed inside. I ended up giving an impromptu geography lesson, and afterward I made a few photographs of the students.

Several years later, one of those photographs was chosen for the back of a Burundian banknote—a reminder that memorable moments in travel are the ones you never plan.