Built between 1897-1911, the New York Public Library Main Branch is likely the most famous library in the world. Designed by architects Carrère and Hastings it contains 646,680 square feet of interior space. Two stone lions lie at either side of the stairway to the entrance. The famous pair guarding the entrance were sculpted by Edward Clark Potter. Their original names, "Leo Astor" and "Leo Lenox" (in honor of the library's founders) were transformed into Lord Astor and Lady Lenox, and in the 1930s they were nicknamed "Patience" and "Fortitude" by Mayor Fiorello La Guardia, who chose the names because he felt that the citizens of New York would need to possess these qualities to see themselves through the Great Depression.