Serendipity describes a happy coincidence that allows us to discover what we were not even looking for. The precondition for discovery is that we recognize the significance of our accidental observation and take a second look. When designing, constructing and on excursions, students constantly make unexpected discoveries. However, they must also learn to perceive these as relevant events. The lecturers should help students to learn such recognition. However, it is in the nature of things that serendipity cannot be planned.