Nichols Arboretum (123 acres, 49.7 hectares) is an arboretum operated by the University of Michigan. Located on the eastern edge of its Central Campus at 1610 Washington Heights in Ann Arbor, Michigan, the Arboretum is a mosaic of University and City properties operated as one unit. The arboretum is open daily from sunrise to sunset with no charge for admission. The Huron River separates a northern section of the arboretum's floodplain woods; the railroad marks the northern border.