Squantum Marshes are coastal wetlands that cover an area of about 2.5 square miles. The marshes are part of the Neponset River Estuary, which drains into Boston Harbor. Squantum Marshes is an important habitat for migratory and resident waterfowl, as well as a recreational area for boating, fishing, and birdwatching. The marshes also provide flood control and water quality benefits for the surrounding communities. Squantum Marshes is managed by the Massachusetts Department of Conservation and Recreation, with the help of local volunteers and environmental groups.

Squantum is a neighborhood of Quincy connected to the mainland by a causeway that crosses over a wetland area of the bay. Often thought of as a peninsula, Squantum proper is technically a barrier island as it is surrounded on all four sides by water and is only connected to the mainland and Moon Island via causeways. Located in the northernmost portion of the city, Squantum is bordered on the north by Dorchester Bay and Boston Harbor, on the east by Moon Island and Quincy Bay, on the south by Quincy Bay and North Quincy, and the west by the Marina Bay development.

Squantum has scenic, waterfront views of Boston Harbor and the Boston skyline. The neighborhood is further characterized by its tree-lined streets, its "island getaway" feel, its close-knit community, and its annual Squantum Fourth of July Parade.