Spectacle Island is a 105-acre island in Boston Harbor, 4 miles (6.4 km) offshore of downtown Boston, Massachusetts. It is part of the city of Boston. The island has a varied history, and today is a public park with a marina, visitor center, cafe, lifeguarded swimming beach, and five miles of walking trails, forming part of the Boston Harbor Islands National Recreation Area. It is served all year by ferries from Boston, and on weekends and summer weekdays by a shuttle boat to and from nearby islands.
The island was initially composed of two small drumlins connected by a spit, with an approximate size of 49 acres (200,000 m2). The name is believed to derive from its then-resemblance to a pair of spectacles. However, dumping of trash and dirt, together with subsequent landscaping, have resulted in a significantly larger island with a permanent size of 85 acres (340,000 m2), plus an intertidal zone of a further 28 acres (110,000 m2).
The island is now composed of two artificial earth mounds, terraced with retaining walls, roads and newly planted vegetation. With a height above sea level of 157 feet (48 m), Spectacle Island is now one of the highest points on Boston Harbor. The island's inner harbor acreage is 114, with 85.5 upland acres and 28.4 intertidal acres.
Starting in the early 19th century, the island was used exclusively for its relative remoteness from Boston. Two hotels were built in 1847, only to be closed by police ten years later when it was discovered they were used for gambling and other illicit activities.
A horse rendering plant was built on Spectacle Island in 1857, followed by a city trash incinerator that remained active until 1935. When the incinerator closed, trash was simply dumped on the island for the next thirty years. A bulldozer was supposedly swallowed up by the trash sometime during the 1950s. The island remained a smelly, leaking dump until the 1990s.