Washington Square Arch with No. 1 Fifth Avenue behind. March 3, 1929.

The Washington Square Arch, a Tuckahoe marble triumphal arch designed by Stanford White, commemorates the centennial of George Washington’s inauguration as President.

William Rhinelander Stewart, a Washington Square resident, had erected a wood and plaster arch in 1889. After Stewart’s temporary tribute proved popular, White was commissioned to design a permanent monument, which was completed in 1892.

The arch includes a little-used 102-step spiral staircase inside its western end, leading to an skylit attic room and rooftop.