Caumsett State Historic Park, situated on a scenic peninsula extending into Long Island Sound, offers miles of bridle paths, walking, jogging, hiking, biking, cross-country skiing and nature trails over acres of woodland, meadows, rock shoreline and salt marsh. The park has beautiful gardens, excellent fishing and scuba diving by permit.

In 1921 Marshall Field III purchased 1750 acres of Lloyd Neck to create one large estate. He named the land after its Matinecock Indian name, Caumsett, which means "place by a sharp rock."

Field created a self-sufficient English-style estate as a combination country club, hunting preserve, and home, complete with its own water and electrical supply. When the estate was finished, it had facilities for every sport except golf.

Caumsett State Historic Park was acquired by New York State in 1961. The park is diverse; fishing, hiking, bird watching, nature photography, and nature study are among the many activities visitors may pursue. Guided nature tours focusing on many aspects of the Caumsett environment and Long Island in general are led throughout the park. The former Marshall Field III Main House first floor is now open to the general public on weekends. The polo pony barn provides lessons, boarding & equestrian services as part of the Willow Tree Farm Equestrian Center. The summer cottage houses the Nassau BOCES Outdoor and Environmental Education Program. The Volunteers for Wildlife Hospital and Education Center is located in the "Calf Barn" of the park's Dairy Complex which provides rehabilitation and hospitalization for Long Island's injured wildlife. The historic Henry Lloyd Manor house built in 1711 is leased to the Lloyd Harbor Historical Society. The Historical Society provides historic interpretation of life during the colonial period.