Deer Island (Massachusetts)

Deer Island is a peninsula in Boston, Massachusetts, United States. Since 1996, it has been part of the Boston Harbor Islands National and State Park. Although still an island by name, Deer Island has been connected to the mainland since the former Shirley Gut channel, which once separated the island from the town of Winthrop, Massachusetts, was filled in by the 1938 New England hurricane. Today, Deer Island is the location of the Deer Island Waste Water Treatment Plant, whose 150-foot-tall (46 m) egg-like sludge digesters are major harbor landmarks.

During King Philip's War, the island was used as an internment camp for hundreds of indigenous people, and many died. Today, Native Americans commemorate the loss by returning to Deer Island on an annual basis.