The new One South Dearborn office tower glows like a beacon as it soars above the Loop's historic buildings. A square cutout with a tilting wall of frosted glass accentuates the building's summit. Glass walls at the entrance of One South Dearborn allow pedestrians outside to view an art feature inside the lobby, a pair of richly textured, cast-glass walls. The lobby also includes white and gray marble, and recycled glass set into the floor. Office floors feature floor-to-ceiling windows, with diagonal window bays in the northwest and southeast corners.