This document is about a classroom project on the rainbow (Arc de Sant Martí in Catalan). It includes a discussion where the students shared what they already knew about rainbows, questions they had, and an index of topics they wanted to research. It then describes some of the activities they did as part of the project, including listening to legends and stories about rainbows, discussing the stories, and trying experiments to learn how rainbows form. The document emphasizes that the students were motivated and enjoyed deciding as a group what to learn and finding information through different sources.