In the Palace of Assembly, Le Corbusier uses natural light as a dynamic architectural material to bring the cavernous, raw concrete (béton brut) interior to life. By introducing sunlight from above through dramatic roof apertures, high-level slits, and deeply recessed geometric concrete sun-shades (brise-soleil), he creates a striking play of sharp shadows and bright highlights that accentuates the textured, sculptural quality of the space. As these beams of light shift across the massive grid of slender pillars (pilotis) and the sloping walls of the assembly chamber, they constantly alter the perception of the hall, turning a heavy concrete void into an ever-changing landscape of depth and time.