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.
The Smithsonian Institution has two museums of Asian art: the Freer Gallery of Art and the Arthur M. Sackler Gallery. The Freer Gallery houses one of the premier collections of Asian art, with objects dating from Neolithic times to the early 20th century, as well as the world's most important collection of works by James McNeill Whistler. The Freer is currently closed for renovations and will reopen in October 2017.