The Interdisciplinar STEAM Lessons at School (ISLES) is formed by the association of four secondary schools from different countries (Spain, France, and Italy) with extensive experience participating in national and European STEM initiatives. This is the first collaboration between the partners and complements initiatives addressed individually: Erasmus + STEM projects (DICES, CSS, MATH3.0) and European projects (Science on Stage, Europeana, Scientix, eTwinning).