Flax Pond is a tidal estuary which lies behind a barrier beach at the center of Old Field Village, Setauket, NY. One hundred and thirty-five acres of salt marsh, it is a place of great biodiversity and natural beauty. Flax Pond is a habitat for a range of plant and animal species which depend on the tidal rhythms of the estuary for their life cycle. It is a nursery, a shelter, a food source, and a place of continuing renewal.

Flax pond is owned by the New York state Department of Environmental Conservation. Access permits can be applied for at the DEC stony brook university office