“One School, One Forest” is a living STEAM learning laboratory, integrating science, technology, engineering, the arts and mathematics through an interdisciplinary and applied approach. Through the creation of a Miyawaki-style forest, pupils are engaged in the observation, investigation and interpretation of ecosystems, biodiversity and the water cycle, using scientific working methods and digital monitoring tools. The project promotes the collection and analysis of real-world data, enabling an understanding of how natural systems function and the impacts of climate change, as well as the importance of nature-based solutions. The natural engineering aspect is evident in the design and implementation of the forest, whilst the artistic component enhances communication, awareness and creative expression regarding environmental issues, making learning more meaningful and engaging. This educational process develops essential 21st-century skills, such as critical thinking, problem-solving, collaboration, creativity and active citizenship. By involving pupils, teachers, the educational community and partners, the project promotes a strong environmental awareness and a commitment to sustainability. In collaboration with the Water Efficiency Observatory, it reinforces the integration of water, climate and biodiversity, contributing to the resilience of local areas. It is a scalable, replicable project aligned with the Sustainable Development Goals, with particular emphasis on SDG 13 – Climate Action and SDG 15 – Life on Land.