The observatory features floor-to-ceiling glass windows where visitors can step right to the edge of the art deco skyscraper.
Made up of 24 crystal-clear, eight-floor-tall windows, the observation deck is an enclosed, climate-controlled, all-weather one.
It allows 360-degree views to the city and beyond from 381 meters above street level.
Anthony E. Malkin, chairman and CEO of Empire State Realty Trust, said all the obstructions and obstacles were removed in order to give visitors a centrally-located and unrivaled view of the city.
The 102nd floor is the third phase of the building's top-to-bottom reimagined Observatory Experience.
In July, the building unveiled a new set of immersive exhibits to the public in the 10,000-square-foot (about 929 square meters) galleries on the second floor.
The highlighted exhibitions include "The Site in the 1920s," where a black-and-white panoramic image depicts the site of the original Waldorf-Astoria Hotel as construction of the Empire State Building begins, and "Urban Campus," which offers a glimpse into some of the major tenant spaces, amenities, and hidden views of the building as experienced by those who work there.