The Secondary level and plan for university also support exploration of the real world extending it beyond the classroom, into the community and eventually to the world at large. Because they want this discovery to include both the natural world and the world of human civilization superimposed on nature, Montessori called the adolescents ‘Erd Kinder’ or ‘Children of the Earth’ and the program for this age group goes by this name.

Montessori singled out farming activities for their benefits as farming can help students study living nature develop a clearer understanding of the basis of human commerce and economic exchange and the complex issues which they represent for modern society. To facilitate contact with nature, Montessori envisioned a rural although not isolated setting for the Erd Kinder.