Boston Harbor is a natural harbor and estuary of Massachusetts Bay, located adjacent to Boston, Massachusetts. It is home to the Port of Boston, a major shipping facility in the Northeastern United States.
The harbor is sheltered from Massachusetts Bay and the open Atlantic Ocean by a combination of the Winthrop Peninsula and Deer Island to the north, the hooked Nantasket Peninsula and Point Allerton to the south, and the harbor islands in the middle. The harbor is often described as being split into an inner harbor and an outer harbor.
The harbor itself comprises 50 square miles (130 km2) with 180 miles (290 km) of shoreline and 34 harbor islands.
Inner harbor
The inner harbor was historically the main port of Boston and is still the site of most of its port facilities as well as the Boston waterfront, which has been redeveloped for residential and recreational uses. The inner harbor extends from the mouths of the Charles River and the Mystic River, both of which empty into the harbor, to Logan International Airport and Castle Island, the latter now connected by land in 1928 to Boston, where the inner harbor meets the outer harbor.
Outer harbor
The outer harbor stretches to the south and east of the inner harbor. To its landward side, and moving in a counterclockwise direction, the harbor is made up of the three small bays of Dorchester Bay, Quincy Bay and Hingham Bay. To seaward, the two deep water anchorages of President Roads and Nantasket Roads are separated by Long Island. The outer harbor is fed by several rivers, including the Neponset River, the Weymouth Fore River, the Weymouth Back River and the Weir River.
Dredged deepwater channels stretch from President Roads to the inner harbor, and from Nantasket Roads to the Weymouth Fore River and Hingham Bay via Hull Gut and West Gut. Some commercial port facilities are located in the Fore River area, an area which has a history of shipbuilding including the notable Fore River Shipyard.
