The Arnold Arboretum of Harvard University is a botanical research institution and free public park, located in the Jamaica Plain and Roslindale neighborhoods of Boston, Massachusetts. Established in 1872, it is the oldest public arboretum in North America.[2] The landscape was designed by Charles Sprague Sargent and Frederick Law Olmsted and is the second largest "link" in the Emerald Necklace. The Arnold Arboretum's collection of temperate trees, shrubs, and vines has a particular emphasis on the plants of the eastern United States and eastern Asia,[3] where arboretum staff and colleagues are actively sourcing new material on plant collecting expeditions.[4] The arboretum supports research in its landscape and in its Weld Hill Research Building