Smith Estate, also known as Longwood Estate - Smith House, is a historic estate located at Ridge in Suffolk County, New York. It is preserved and maintained by the Town of Brookhaven. The Longwood Estate is part of a huge parcel of land originally purchased by William "Tangier" Smith in the 17th century, which he called Manor St. George. The estate consists of a large, late 18th century main house (altered and enlarged during the 19th century), caretaker's cottage, a farm complex (of barns and sheds dating from the late 18th through early 20th centuries), the Smith family cemetery, and a small frame schoolhouse moved to the property in 1977. It was added to the National Register of Historic Places in 1981.