Just inside the main lobby of City Hall, the soaring rotunda is dramatically encircled by a keystone-cantilevered marble staircase, one of the first of its kind in the country and a feat of engineering ingenuity. The staircase rises from the lobby to the second floor, where 10 Corinthian columns support the coffered dome and oculus above, recalling the Pantheon in Rome. The marble flooring and decorative iron balustrade add to the rotunda's grandeur.