Great Brewster Island is one of the outer islands in the Boston Harbor Islands National Recreation Area, situated some 9 miles (14 km) offshore of downtown Boston. The island has a permanent size of 18 acres (73,000 m2), plus an intertidal zone of a further 49 acres (200,000 m2). Unlike the other outer islands, which are low-lying outcroppings of bedrock, Great Brewster is a drumlin which reaches a height of over 100 feet (30 m) above sea level. It has vegetation cover consisting of Apple Trees, Pear Trees, Sumac, Beach Roses, Grasses and Common Reeds, together with a large Gull colony. The birds are aggressive during nesting season and access by humans, which is by private boat only, is discouraged during that time.
Like the neighbouring islands of Little Brewster, Middle Brewster and Outer Brewster, Great Brewster Island is named after William Brewster, the first preacher and teacher for the Plymouth Colony. In 1891, in what was considered a radical action for the time, four women spent two weeks on the island and documented their visit. More recently the island has been home to summer cottages for local families and for soldiers who manned an observation post during World War II. The military post included rapid-fire guns, searchlight stations, and a command post that aided in controlling the harbor’s minefield.
Brewster Island (64°43′S 62°34′W / 64.717°S 62.567°W / -64.717; -62.567Coordinates: 64°43′S 62°34′W / 64.717°S 62.567°W / -64.717; -62.567) is a small island lying northeast of Danco Island in Errera Channel, off the west coast of Graham Land. It was shown on an Argentine government chart of 1950, and named by the UK Antarctic Place-Names Committee in 1960 for Sir David Brewster, Scottish natural philosopher who in 1844 improved the mirror stereoscope invented by Sir Charles Wheatstone by substituting prisms.