The Rotunda served as the entrance to the Library during Morgan’s lifetime. For the visitor who entered from the street, the austere monochromatic façade would suddenly yield to a soaring, well-lit space, sumptuous in its profusion of colored stones and jewel-toned paintings.
Vertical panels of mosaic tiles adorn the walls, alternating with marble pilasters. Free-standing marble columns are topped with alabaster bowls. And rich blue columns clad in tiles of lapis lazuli flank the small door, over which is mounted a blue-and-white glazed Renaissance relief. The central oculus illuminates the surrounding painted dome and the relief panels in the blue and white stuccoed apse, as well as three painted lunettes.