Winter Island reaches out from Salem Neck on a causeway, about 45 acres of shore and marine park. The island is about 45 acres (18 ha) in size and sits hemmed in by Smith Pool to the northwest, Cat Cove to the west, Salem Channel to the south and east, and Juniper Cove to the north. At the north end you can see about a dozen residences clustered along the single road, Winter Island Road.
On the northeastern shore the Plummer Home for Boys, now Plummer Youth Promise, occupies 18 acres (7.3 ha); the balance of the island is Winter Island Marine Park. The entire island was added to the National Register of Historic Places as the Winter Island Historic District and Archeological District in 1994. The marine park sits on the former site of the Coast Guard Air Station Salem and takes up the southern portion of the peninsula.
Its main attractions include historic Fort Pickering, which is listed separately on the National Register, the Fort Pickering Lighthouse, broad views over Salem Harbor, a boat launching ramp, and the former Coast Guard seaplane hangar and barracks. A master plan was developed in 2011. Notice Fort Pickering, its lighthouse, and Salem Harbor opening at the island's southern tip.