The Smithsonian Institution began construction in 1847 and was completed in 1855. It features many museums centered around history, art, culture and science. Two of the most popular museums are the National Museum of Natural History, which explores human origins and wildlife, and the National Air and Space Museum, home to famous aircraft like the Wright Flyer and Spirit of St Louis. Both museums are located on the National Mall in Washington, D.C. and offer free admission daily from 10am to 5:30pm.