Island Facts


Learn about the Islands of Boston Harbor

Explore the map to learn the history of the Boston Harbor Islands. Choose an island below for details about each of the islands in the park.


The Islands

  • field of green bushes with yellow flowers overlooking the water.
    Bumpkin Island

    Walking trails and the remains of an old stone farmhouse make up the landscape of this picturesque island.

  • Map of Hingham Bay with Button Island highlighted
    Button Island

    This small island features a rock-strewn gravel beach and a large oak tree.

  • Marsh with reeds and other tall grasses and vegetation.
    Calf Island

    Tidal marshes, wildflowers, tall grasses, and wild fruit trees are some of the varying aspects of Calf Island.

  • walkway with a grassy hill in autumn. White orbs and a wind turbine in the background.
    Deer Island

    On Deer Island, tour the “state of the art” wastewater treatment facility or stroll 60 acres on the shoreline path.

  • aerial view of an island with trees and some bushes. A pier and a rocky beach in foreground.
    Gallops Island

    This small island offers a rocky beach, salt spray roses, and vistas from atop grassy bluffs.

  • parade ground with a concrete bastion of a fort.
    Georges Island

    Explore the Civil War-era Fort Warren, enjoy a picnic lunch, or relax under a shady tree on Georges Island.

  • View from the water of a pier, rocky beach, and forested area on an island.
    Grape Island

    Wander peaceful trails, explore the rocky beaches, and enjoy camping in wooded campsites.

  • A rocky outcropping with a lone lighthouse.
    The Graves

    This rocky ledge is home to the outermost lighthouse in Boston Harbor.

  • a rocky beach next to an eroding sandy bluff.
    Great Brewster Island

    This largest of the Brewster islands features eroding cliffs, a salt marsh, tidal pools, and a large gull colony.

  • A rocky outcropping with gulls and some low grass.
    Green Island

    This shrub-covered rocky outcropping serves as a nesting site for gulls and cormorants.

  • Rocky beach looking towards a small rocky outcropping.
    Hangman Island

    A barren rock outcrop with a small pebble beach serves as a resting-place for the gulls, ducks and other seabirds.

  • A forested island with sandy bluffs.
    Langlee Island

    With grassy patches under shaded maple, cedar, and birch trees, visitors can enjoy hiking on the island.

  • A small, rocky island with a lighthouse station, lighthouse, and other small white buildings.
    Little Brewster Island

    Home to Boston Light, the oldest lighthouse site in the country.

  • Overlooking the harbor with a small rocky outcropping.
    Little Calf Island

    This tiny bedrock outcrop was never inhabited by people, but gulls and cormorants use it for nesting.

  • A white and red-checkered watertower and a brick building sit atop a bluff of an island.
    Long Island

    This large island is home to Long Island Head Light and the now closed City of Boston social services facilities.

  • View of walking on a wooden pier to a sandy beach with tall grass on either side.
    Lovells Island

    A rocky swimming beach, pine woods, and the remains of a fort characterize Lovells Island.

  • A stone archway amidst a grassy knoll. Birds flying around in the background.
    Middle Brewster Island

    This rugged Island, once home to a colony of fishermen, now is a haven for wildlife.

  • A sewage area overrun with grass and shrubs.
    Moon Island

    This island serves as a firefighter training facility and police firing range.

  • A large black and white cone-shaped marker on top of a brick stand on a tiny island.
    Nixes Mate

    Pirate lore surrounds this black and white marker which has guided boat traffic for a century.

  • A paved walkway with a grassy area and benches to the left and low bushes to the right.
    Nut Island

    Beautiful harbor vistas are found on this peninsula which houses a wastewater pumping station and landscaped park.

  • A rocky shoreline juts into the water. Low grass in the foreground.
    Outer Brewster Island

    This bedrock island supports the most diverse assemblage of breeding waterbirds in Boston Harbor.

  • An island coastline with a pebble beach and low grass. A white chapel and trees in the background.
    Peddocks Island

    This large island features military ruins, varied habitats, scenic hiking trails, and overnight camping.

  • A map of Massachusetts Bay near Houghs Neck, with Raccoon Island highlighted.
    Raccoon Island

    This small island is characterized by gravel beaches and rocky slopes.

  • A rocky and pebbly beach overlooking the water.
    Ragged Island

    This little island is enjoyed by many for quiet reflection.

  • Aerial shot of an island composed of two triangles connected by a spit of land.
    Rainsford Island

    A variety of wildflowers brighten the landscape of Rainsford Island.

  • Trees filled with birds' nests pop up from vibrant green bushes.
    Sarah Island

    This island's ledges, beaches, and mudflats make the ideal nesting place for gulls.

  • Bedrock ledges with groups of birds pop up from the water.
    Shag Rocks

    Located among the Brewsters, these bedrock ledges have long been a danger to mariners.

  • A small island with a pebbly beach and low brush. Lots of birds flying and resting on the beach.
    Sheep Island

    Once 25 acres, Sheep Island has been eroded away to less than 2 acres by wind and water.

  • Island with tall brass and other low vegetation.
    Slate Island

    Slate Island in Hingham Bay has remained relatively inaccessible due to the dense thickets of poison ivy, raspberry, and barberry.

  • Winter scene of a pebbly shoreline with reeds and tall grass.
    Snake Island

    This island's mudflats and grassy clearings offer excellent off-shore birding opportunities.

  • View from drumlin overlooking the coast of Spectacle, with boats and a dock.
    Spectacle Island

    Spectacle Island offers several miles of hiking, a visitor center with exhibits, and a swimming beach.

  • Tall coastal grass blowing in the wind against a blue sky.
    Thompson Island

    This island of diverse habitats is home to Thompson Island Outward Bound Education Center.

  • A wooden bridge leads to a gravel trail. Tall grass on a hill in the background.
    Webb Memorial State Park

    Walking trails lead through flowering trees and shaded picnic areas to excellent fishing locations at Webb Memorial State Park.

  • Winter scene of two hills connected by a spit of land. Bare trees dot the landscape.
    World's End

    The landscape plantings and roads of this large peninsula were designed by Frederick Law Olmsted.

The sizes of the islands in the park change every hour, as the ocean tides ebb and flow on their shores. All totaled, the park islands change from 1,483 to 3,067 acres during the tidal cycle. Learn how island acreage was measured, considering daily tides.

The names of several islands have also changed over time. How we selected the spelling of island names, and alternate names for some islands, are described in, "What's in a name?"

Last updated: October 30, 2023

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