The Thain Family Forest is a 50-acre section of old-growth forest along the Bronx River in the New York Botanical Garden, for a time known as the Native Forest and historically as the Hemlock Grove. Its heritage dates in part to pre-colonial Lenapehoking. New York City acquired 4,000 acres as parkland in 1888, and in 1895 the New York Botanical Garden site was chosen here primarily due to the presence of the forest, which covers about one-fifth of the garden grounds.