The topic of monuments and memorials is extremely connected to the paradigm of sustainability. Monuments are made to last, but do we still know after some time what they stand for? Are their aims and meanings sustainable? How can we deal with this setting today? How can we contribute to a wider discourse on monuments and memorials? During the lockdown in spring 2020, students from various semesters and fields of study at the Lucerne School of Art & Design explored these central issues and investigated phenomena of the Lucerne Lion Monument. L21 provides insights into this approach, which is both processual and comprehensive.