The negative consequences of human action on the environment reached an unprecedented level at the beginning of the 21st century, with the extinction of thousands of animal and plant species and the depletion of natural resources vital to society. This work describes a methodological proposal for an entrepreneurial environmental education action, the creation of environmental maps of the surroundings of school buildings by the students and teachers themselves, based on field research and data analysis carried out by the students. The methodology consists of three stages, the first being Pedagogical Preparation, when the students are introduced to the project and equipped with data collection methods; the second, Fieldwork, in which the students walk around the community surrounding the school collecting data; and the third, Data Processing, which is systematised in the free software package Libre Office to compose the report that will give rise to the School Environmental Map. The conclusion is that this methodology is feasible for public school teachers in general, as it is possible to create the Environmental Map at practically zero cost, with short and long-term benefits.