Island Beach State Park is a New Jersey state park located just south of Seaside Park on the Barnegat Peninsula in Berkeley Township, Ocean County, New Jersey, United States. The park is operated and maintained by the New Jersey Division of Parks and Forestry. Most of the park encompasses the former borough of Island Beach.
The park is the largest reserve of undeveloped barrier island in New Jersey and one of the largest in the United States. The park is divided into two areas. The Island Beach Northern Natural Area covers 659 acres (2.7 km2), some of which is restricted to the public. The Southern Natural Area is much larger at 1,237 acres (5 km2). The park includes the Sedge Island Marine Conservation Zone, which includes about 1,600 acres (6 km2) of tidal marshes, creeks, ponds, and open water.
Coming in from the sea-front, a visitor ascends over a large primary dune covered in tall grasses and down into a narrow maritime forest, consisting of many tall bushes and short trees including holly, goldenrod and black cherry. Approaching the bay side, one finds reeds and a muddy estuary that is home to blue crabs and herons and other marine birds. The park is an excellent site for bird watching with osprey nests and bird blinds set up. The Barnegat Inlet is located at the southern tip of the park, separating the Barnegat Peninsula from Long Beach Island.
Swimming, kayaking, and fishing are permitted in some areas of the park. Four wheel drive vehicles are permitted onto the beach with a permit.