The document summarizes Hector Guimard's design of the entrances for the Paris Metro system from 1899-1905. It discusses that Guimard designed the entrances in the Art Nouveau style using cast iron and glass. He created three types of entrances - open, covered, and enclosed. A total of 141 entrances were constructed, with 86 still existing today. The entrances featured curving lines and floral motifs inspired by nature.