Opened in 1910, the museum on the National Mall was one of the first Smithsonian buildings constructed exclusively to hold the national collections and research facilities. It is administered by the Smithsonian Institution and admission is free. It is the most visited museum in North America. The main building has an overall area of 1,320,000 sq.ft. with 350,000 sq.ft. of exhibition and public space and over 1,000 employees. The museum’s collections total over 126 million specimens of plants, animals, fossils, minerals, rocks, meteorites, and human cultural artifacts.