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.
In March 2016, Smithsonian officials said the project's cost had risen to $600 million. In late June 2016, Smithsonian officials projected the museum's renovation to cost $1 billion. This included $676 million for construction, $50 million to build new storage space, and $250 million for new exhibits.