Astor Hall is the first-floor lobby, reached from the portico at the top of the stairs to Fifth Avenue.
The hall measures 70 by 44 feet (21 by 13 m) in floor area, and its ceiling is 34 feet (10 m) above the floor.
The entirety of the space is made of stone, and the ceiling of the hall is a low barrel vault with arch openings on the sides.
The names of major donors are inscribed on the pillars in Astor Hall.

Two grand marble staircases on the north and south sides of Astor Hall ascend to the second floor.
There are bronze busts of Carrère and Hastings, created in 1940 and 1935 respectively, at the bottom of the stairways that lead from Astor Hall.
Facing westward from the entrance, the Carrère bust is located near the stair on the south side, while the Hastings bust is located near the stair on the north side.
The staircases ascend several steps, perpendicular to and away from the hall, before turning 90 degrees westward and ascending parallel to each other for the rest of the flight to the second floor.
At the top of the flight, another identical pair of staircases, which are perpendicular to the staircases leading from the Astor Hall, leads from the second floor to the McGraw Rotunda on the third floor.
Astor Hall is the first-floor lobby, reached from the portico at the top of the stairs to Fifth Avenue. The hall measures 70 by 44 feet (21 by 13 m) in floor area, and its ceiling is 34 feet (10 m) above the floor. The entirety of the space is made of stone, and the ceiling of the hall is a low barrel vault with arch openings on the sides. The names of major donors are inscribed on the pillars in Astor Hall.
Two grand marble staircases on the north and south sides of Astor Hall ascend to the second floor. There are bronze busts of Carrère and Hastings, created in 1940 and 1935 respectively, at the bottom of the stairways that lead from Astor Hall. Facing westward from the entrance, the Carrère bust is located near the stair on the south side, while the Hastings bust is located near the stair on the north side. The staircases ascend several steps, perpendicular to and away from the hall, before turning 90 degrees westward and ascending parallel to each other for the rest of the flight to the second floor. At the top of the flight, another identical pair of staircases, which are perpendicular to the staircases leading from the Astor Hall, leads from the second floor to the McGraw Rotunda on the third floor.
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