Established in 1872 and designed in collaboration with landscape architect Frederick Law Olmsted, the Arnold Arboretum is a National Historic Landmark. Founded as a partnership between the City of Boston and Harvard University, the Arnold Arboretum is a unique blend of a respected research institution and beloved public park in Boston's Emerald Necklace. Occupying 281 acres, its living collection of trees, shrubs, and woody vines is recognized as one of the most comprehensive and best documented of its kind in the world. Its lilac collection is a springtime favorite of visitors, along with the magnificent rhododendrons, and in the fall, trees from maples to dawn redwoods provide a wonderful display of color. The living collection is supported by curatorial documentation, a herbarium, library and archival holdings, and a state-of-the-art research center. These facilities and holdings provide the basis for research and education of visitors, students, and scholars from around the world.