Sitting in Dorchester Bay, just beyond Thompson Island is Thimble Island. A small rocky outcropping, it once served as the middle shaft for a sewage tunnel. Little else is known about the island.1
Footnotes
1.
Edward Snow, The Islands of Boston Harbor (Carlisle, MA: Commonwealth Editions, 2002), 104; Boston Harbor Beacon, “Moon Island and the Old Boston Drainage System," last modified Jan. 25, 2015, accessed April 18, 2023, Moon Island.
Boston Harbor Islands National Recreation Area
Source: U.S. Department of the Interior, National Park Service