Boston Harbor Islands
The Boston Harbor Islands is a national park that includes 34 islands that lie within the large "C" shape of Boston Harbor in the state of Massachusetts. It is site of a Swim Across America 22-mile charity relay called the Boston Harbor Swim.
The islands have been closely linked to Massachusetts Bay and to coastal communities for thousands of years. The land mass of the Boston Harbor Islands totals approximately 1,600 acres at high tide and 3,100 acres at low tide. The Boston Harbor Islands national park area extends seaward 11 miles from downtown Boston and form a transition between the open ocean and the settled coast.
The 34 islands of Boston Harbor (ranging in size from less than 1 acre to 274 acres) have served numerous public and private uses and are a unique example of an island cluster intimately tied to the life of a city. Although within sight of a dynamic and densely populated metropolitan area, they continue to offer the visitor a rare sense of isolation. Their proximity to a large urban population and their special natural and geologic resources, cultural and historic resources, and associated values contribute to their national significance.