The present sheet invites the viewer into the “marvelous” dwelling of a group of mythological water nymphs. This three-story cavern, illuminated by an oculus, forms a microenvironment replete with water jets, singing birds, and plants growing on compost. A surrounding aqueduct supplies the water for the monumental cascade. Lequeu’s annotations note that the grotto, half-disguised as an artificial mound above ground, was to be situated at the end of a cloister and in front of a labyrinth, an elaborate and entirely imaginary setting.