UNDERLIGHT at Llum Barcelona 2026
UNDERLIGHT, a public installation that brought the hidden infrastructures of the city into view, developed within the Master in Design for Emergent Futures.
Revealing the city beneath the city
For the fifteenth edition of Llum Barcelona, IAAC Fab Lab Barcelona presented UNDERLIGHT, a public installation that brought the hidden infrastructures of the city into view. Developed within the Master in Design for Emergent Futures (MDEF), the project was curated by Mario Santamaría in collaboration with Saúl Baeza, Chiara Dall’Olio and Guillem Camprodon, and designed and produced by IAAC second-year master students.
Installed at Castella 9, in the neighbourhood of Poblenou, UNDERLIGHT occupied a small public plot shaped by decades of neighbourhood activism. Once home to an electrical transformer station that powered the area’s industrial growth, the site now exists in a state of suspension, open yet unresolved, accessible yet awaiting a permanent civic role. This condition became the conceptual starting point of the project.
From spectacle to substrate
Within a festival dedicated to light as both medium and metaphor, UNDERLIGHT shifted attention away from illumination as spectacle and toward the systems that make light possible. The square was transformed into a fictional roadworks site: barriers, signage and monitoring screens evoked the language of maintenance and repair.
Visitors encountered what appeared to be a live video feed from a small robot navigating underground pipes beneath the plaza. The descent felt immediate and authentic, yet it unfolded inside a concealed model. This deliberate ambiguity exposed a key tension: infrastructure is everywhere, shaping daily life, yet it remains hidden, abstracted or inaccessible.
By staging a simulated inspection, the installation invited the public to observe, monitor and interpret what lay below their feet. In doing so, visitors temporarily adopted the role of maintenance workers. Observation became participation.
Maintenance as a public matter
UNDERLIGHT foregrounded a question that is rarely asked in celebratory narratives of urban innovation: who maintains the city? Whose labour remains unseen?
The act of upkeep, often invisible and undervalued, was reframed as a shared civic responsibility. Rather than presenting infrastructure as a neutral technical system, the project positioned it as a cultural and political substrate of urban life. Energy networks, underground pipes, and repair practices entered the public imagination not as background operations but as contested terrains.
The project resonated closely with the practice of Mario Santamaría, whose work explores technologies of vision, mediation and infrastructure. Known for making abstract networks tangible, notably through Internet Tour, an initiative founded in 2018 that organises guided visits to the physical infrastructure of the internet, Santamaría brings attention to the material realities behind systems often perceived as immaterial.
Pedagogy in public space
Developed collectively at Fab Lab Barcelona, UNDERLIGHT reflects a pedagogical model that treats the city as a site of inquiry. Students from the Master in Design for Emergent Futures worked across architectural experimentation, artistic practice and situated research, engaging with the specific history and condition of Poblenou.
Rather than proposing a finished solution for the square, the installation opened a space for reflection. In the context of Llum Barcelona’s 2026 theme, Night Landscapes, the illuminated city was reframed not as a seamless surface but as a layered environment shaped as much by what lies underground as by what shines above.
UNDERLIGHT ultimately asked visitors to look down and to reconsider the infrastructures that sustain urban life.
