The project 'CLEAN' has dealt with one of the central topics of our time: environmental issues. Although it's a well-known topic for the teachers, future generations will constantly need to develop their own environmental awareness. Through the framework of an international project, the students and teachers involved discovered how the environment is (next to the Sars-cov-2 / Covid 19 pandemic) the biggest global challenge of our time, and how solutions both can and must be found jointly with other countries. Furthermore, they became aware of the fact that whilst sustainable living is a global effort, efforts must also be made locally. Environmental education, concrete sustainable action, and environmental awareness were therefore the primary concerns of the project. The project group was composed of different types of schools from six countries (the Netherlands, the United Kingdom, Italy, Spain, Turkey, and Germany). Some of the schools work in integration, which reflected in the composition of the group involved in the project, with some having a vocational focus while others were more academically orientated. The age group targeted were students between 14-15 years old; the project group was put together with students of these ages. The student body was socially mixed, and the project also involved students from both urban and rural schools. Of course social inclusion was incorporated in composing the project group. The six schools had very different levels of experience with international projects. Some schools were already experienced in both Comenius and Erasmus projects, whereas others were getting their first experience through this project. Viewed as an overall group, the different experiences of the different schools complemented each other well. In the course of the two-year (because of the pandemic three-year) project, the pupils participated in numerous age-appropriate activities. Central to the project was the formation of an 'Eco Green Team' in each school and working on differing themes such as recycling, upcycling, and the use of natural resources. Further important parts of the project were making nature in need of conservation accessible, and creative work around the project theme. To achieve this, photo albums and videos were created, objects were made using recyclable materials, a song was composed and much more. In this way, the pupils learned how to properly use ICT and social media in real-life situations. Furthermore, the international nature of the project made it possible for students to enhance their language skills. At the same time they acquired respect and responsibility for cultural heritage in the different countries, experienced differences in culture, acquired respect for different habits and mannerism and learned to accept all differences. Above all, the project aimed to institute numerous changes to the participating schools through working together. The 'Eco Green Teams' During the project the student’s workgroups met among others with city or town councils. They had the opportunity to share thoughts about e.g. creating a more sustainable environment and dealing with waste with people whose profession it was to seek for solutions in this matter. Next to that the ECO teams worked in the schools to realize and start changing things. In one school they became a structural participant in the taskforce group that was working on a more environmental friendly school building. For instance, because of this participation normal light sources will be replaced by LED sources. Because of the participation in this project being aware of dealing with waste was aroused and became an integral part of the schools' lives. These results proof that each school individually is working on taking their environmental education further.