We took one shot at answering this question on Aug. 12, 2017. But here is another: We are thinking of an outdoor space that offers teaching and learning opportunities that are unlikely to work quite as well indoors, taking advantage especially of stimulation of all the senses, the contribution that contact with nature makes to wellbeing and the real-world experiences that can make learning feel relevant. Perhaps, however, that still does not explain what exactly an outdoor classroom is.
It is worth knowing then that there really is no single definition. The term is used differently by different people, different developers and different schools. A look, however, at how others use the term reveals some pretty exciting possibilities.
The Jeffers Foundation in Minnesota, for example, casts everything on the other side of the schoolhouse window as an outdoor classroom and encourages teachers to bring classes outside to explore and to find creative ways to present the same lessons they teach indoors. The foundation, which describes its mission as supporting environmental stewardship through education, offers tons of great ideas and support material at its web site. We would presumably have to travel to attend one of its signature workshops, titled The Outdoor Classroom; Team Teaching with Mother Nature. But videos and PowerPoint presentations at the web site could really help an enterprising teacher get started.