A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

New York's famed Empire State Building hosted new guests on Saturday night as images of endangered animals were flashed across its facade.

Images are projected onto the Empire State Building as part of an endangered species projection to raise awareness, in New York August 1, 2015. (Photo by Eduardo Munoz/Reuters)

A runner taking part in the 38th Annual Empire State Building Run-Up is pictured arriving on the 86th floor in the Manhattan borough of New York February 4, 2015. (Photo by Carlo Allegri/Reuters)

The Empire State Building towers over the Manhattan skyline as tourists gather on the observation deck of Rockefeller Center on February 13, 2012 in New York City. The owner of the Empire State Building, Malkin Holdings, plans to raise up to $1 billion in an initial public offering on the 102 story Manhattan landmark. (Photo by John Moore/Getty Images)