Smithsonian American Art Museum Landmark located in Washington, D.C.'s downtown cultural district. It is considered an example of Greek Revival architecture in the United States. It was designed by architects Robert Mills, and Thomas U. Walter. During the 1990s, the Smithsonian Institution worked on restoring the building. The Smithsonian completed another renovation of the building in July 1, 2006. The 2000-2006 renovation restored many of the building’s exceptional architectural features: restoring the porticos modeled after the Parthenon in Athens, a curving double staircase, colonnades, vaulted galleries, large windows, and skylights as long as a city block. During the renovation, the Lunder Conservation Center, the
National Museum of Natural History of with of exhibition and public space and houses over 1,000 employees. The museum's collections contain over 126 million specimens of plants, animals, fossils, minerals, rocks, meteorites, human remains, and human cultural artifacts. It is also home to about 185 professional natural-history scientists—the largest group of scientists dedicated to the study of natural and cultural history in the world. The United States National Museum was founded in 1846 as part of the Smithsonian Institution. The museum was initially housed in the Smithsonian Institution Building, which is better known today as the Smithsonian Castle. A formal exhibit hall opened in 1858.