7. The Guastavino Rotunda Holds a 140-Ton Skylight

Mastercraftsman Rafael Guastavino left his mark all over New York City, from City Hall subway station and Grand Central Terminal to the Prospect Park Boathouse. Guastavino’s work appears in the museum as a giant domed ceiling in the massive rotunda under which workers once sat at the large marble counter to collect tariffs. The skylight that is supported by the dome weighs 140 tons. The ceiling is made entirely of plaster and tile using the famous Guastavino method.
During World War II, the rotunda skylight was painted over for safety reasons. This was also the case with the illuminated windows of the original Penn Station as well the Ansonia Hotel, and City Hall subway station.

The two staircases on either end of the lobby were also constructed by the Guastavino Fireproof Construction Company using the same method employed in the construction of the rotunda.