US National Arboretum. Washington, DC.
"[The US National Arboretum was] established in 1927 by an Act of Congress.. The U.S. National Arboretum enhances the economic, environmental, and aesthetic value of ornamental and landscape plants through long-term, multi-disciplinary research, conservation of genetic resources, and interpretative gardens and exhibits." Source: US Arboretum Official Site.
Plan for the newest garden room.