Pelham Bay Park, located in the northeast corner of the New York City borough of the Bronx and extending partially into Westchester County, is at 2,772 acres (1,122 ha) the largest public park in New York City. The section of the park within New York City's borders is more than three times the size of Manhattan's Central Park. It is operated by the New York City Department of Parks and Recreation.
About 600 acres (2.4 km²) are tidal, and fluctuate between being walkable and underwater, due to rapid tide changes in the salt marshes and the receding shoreline of Orchard Beach. The park includes land on both sides of the Hutchinson River, as well as Hunters Island, Twin Island, and Two-Trees Island, all formerly true islands in Pelham Bay and now connected to the mainland by fill. It borders the Bronx neighborhoods of Country Club, Pelham Bay, City Island, and Co-op City.
North of the park is the village of Pelham Manor in Westchester County, and a 250 feet-wide strip of land that is part of New York City due to a boundary error. Owners of the several dozen houses on the strip have a Pelham Manor zip code and phone numbers and their children attend Pelham public schools, but as Bronx residents pay much lower property taxes than their Westchester County neighbors.
The southern part of Rodman's Neck is not part of the park but is occupied by the NYPD Rodman's Neck Firing Range. The City Island Bridge connects the park to City Island. A 19th-century plantation-style mansion called Bartow-Pell Mansion is a colonial remnant done in Greek revival style. It is a National Historic Landmark. The lagoon nearby was once part of Pelham Bay and was called LeRoy's Bay in colonial times. The lagoon was widened and dredged when it was chosen as the site of the 1964 Olympic Rowing trials.
At the northeast section of the park is Orchard Beach and a parking lot that were created by Robert Moses as the Riviera of Long Island Sound. One third of Pelham Bay, from which the park got its name, was filled in with landfill to make Orchard Beach. The park is crossed by the New England Thruway, the Hutchinson River Parkway, and Amtrak's Northeast Corridor railroad.
- Orchard Beach: a 115-acre (0.47 km2), 1.1-mile (1.8 km) Long Beach, man-made under Robert Moses' supervision in the 1930s and the only public beach in the Bronx.
- The Bartow-Pell Mansion and Museum: an elegant example of 19th-century architecture.
- Split Rock: at the Hutchinson River Parkway's intersection with the New England Thruway; legend says that Anne Hutchinson, an early proponent of religious freedom, was killed here.
- The Bronx Victory Column & Memorial Grove: a 75-foot (23 m) tall limestone column supporting a statue of Winged Victory, honoring servicemen from the Bronx who lost their lives defending their country.
- Glover's Rock: a giant rock bearing a bronze plaque commemorating The Battle of Pell's Point during the Revolutionary War.
- Hunter Island: a small island, home to the Kazimiroff Nature Trail.
- Thomas Pell Wildlife Sanctuary: mostly salt marsh; egrets and heron can often be seen.
- The Orchard Beach Nature Center is open on weekends from Memorial Day through Labor Day. The Pelham Bay Nature Center is open for scheduled programs and by appointment.
Thomas Pell Wildlife Sanctuary and the Hunter Island Marine Zoology and Geology Sanctuary consist of a total of 489 acres (1.98 sq km) of marshes and forests within Pelham Bay Park. The City began landfill operations near this area on Tallapoosa Point in Pelham Bay Park in 1963. Plans to expand the landfills in Pelham Bay Park in 1966, which would have created the City’s second-largest refuse disposal site next to Fresh Kills
in Staten Island
, were met with widespread community opposition. This struggle resulted in the creation of the sanctuaries by a local law, signed by Mayor John V. Lindsay on October 11, 1967.
The Thomas Pell Wildlife Sanctuary makes up the westerly part of Pelham Bay Park (2,764 acres). Included within its bounds are Goose Creek Marsh and the saltwater wetlands adjoining the Hutchinson River as well as Goose Island, Split Rock, and the oak-hickory forests bordering the Split Rock Golf Course. The area is home to a variety of wildlife including raccoon, egrets, hawks, and coyotes. The Sanctuary is named for Thomas Pell, the first European to control the land.
Located north of Orchard Beach, the Hunter Island Marine Zoology and Geology Sanctuary encompasses all of Twin Islands, Cat Briar Island, Two Trees Island, and the northeastern shoreline of Hunter Island. It contains many noteworthy geological features including glacial erratics, large boulders that were deposited during the last ice age nearly 15,000 years ago. The rocky coast of Twin Islands, reminiscent of the New England shorefront, is the southernmost outcropping of Hartland Schist, the major bedrock component of such coastlines. The sanctuary supports a unique intertidal marine ecosystem that is rare in New York State.