Drawing on contemporary reconceptualizations of materiality as a site of more-than-human mindfulness, meaning, and moral salience, this chapter brings a material ecocritical perspective to bear on the celebration of caverns, mines, and mining in Novalis's unfinished novel, Heinrich von Ofterdingen. While the German Romantic romance with mining has sometimes been seen as complicit with the emergent extractive economy of industrial modernity, I argue that it is also possible to exhume from Novalis' literary underground an ecophilosophical ethos of human responsibility for more-than-human flourishing that answers to the socio-ecological exigencies of the present, in which "letting be" is no longer adequate.