There’s nothing quite like the Smithsonian Institution, a collection of 19 behemoth, artifact-stuffed museums, many lined up in a row along the National Mall. Rockets, dinosaurs, Rodin sculptures, even the 45-carat Hope Diamond – the city houses a multitude of riches. You can thank James Smithson for the pleasure. The eccentric Englishman bequeathed $508,318 to the USA back in 1826 to create a ‘diffusion of knowledge,’ and it paid off big time. The Smithsonian now holds approximately 140 million artworks, scientific specimens, artifacts and other objects in its trove of museums. In accordance with Mr Smithson's wishes they're all free, always. DC has many more museums beyond the Smithsonian. Freebies include the National Gallery of Art and the haunting US Holocaust Memorial Museum. The government-run National Archives and Library of Congress aren't technically museums, but they hold museum-caliber exhibits. Then there are a handful of admission-charging entities like the impressive Newseum.