In an anthropocynical epoch of severe environmental crisis, geoscientists have unique skills to drive the transition to sustainability. Therefore, the geological literacy of society is essential to seek solutions to major challenges. However, the formal education of geology differs considerably from the desirable. Fortunately, there are out of school organizations in charge of geology outreach. In this work, an analysis and redesign of the teaching material offered by the GeoEskolak program of the Geopark of the Basque Coast is carried out. This material is aimed to 4th grade secondary education students who visit the Flysch of Zumaia. The new "Teacher's Manual" has been developed following the strategy defined by the DBS methodology for the design of a sequence and is adapted to the LOMLOE curriculum and the Sustainable Development Goals.