The claim that the Wall is 300 miles long is further supported in Game of Thrones: A Telltale Games Series, where Britt Warrick says to Gared Tuttle a 300-mile wall, and you're still in my way. The game is canon to the show so it is possible that Sam was wrong.
One of the most respected collections of museums in the world, the Smithsonian Institute is an inspiring attraction for kids, teens and adults. Comprised of 19 different museums, art galleries and research centers, the Smithsonian collection is centered around the National Mall - and admission is always free. The most popular Smithsonian museums include the National Archives, National Zoo, National Museum of Natural History and the National Air and Space Museum.
Smithsonian Institution. Admission is free for all Smithsonian museums and the zoo in Washington, D.C., and the American Indian Museum's George Gustav Heye Center in New York. Tickets are not used for general admission with the exception of the African American History and Culture Museum; visit the museum's website for details.