In 1975, Juan Navarro Baldeweg presented in the exhibition hall of the Center for Advanced Visual Studies (CAVS) of the Massachusetts Institute of Technology (MIT) the installation Interior IV (1975), in which he clearly manifested the need to capture the imprint of the body in an empty room, through the superposition of some lines drawn on the walls of the room. After a series of exhibitions focused on activating the environment, based on variables such as light or gravity, in this installation, there was an explicit manifestation of the body, establishing a turning point towards interventions on the environment that emanate from his own body arising from his own gestures, as a manifestation of the individual and the organic. From that moment on, the exploration of this new variable became a constant in his professional career. A study of this installation can lead us to a greater understanding of the foundations of the artistic universe of this creator and of some of the motivations that have guided his work since then.