Governors Island

Governors Island is a 172-acre (70 ha) island that lies on the Upper New York Bay, about one-half mile (1 km) from the southern tip of Manhattan Island and away from Brooklyn by Buttermilk Channel. It is legally part of the borough of Manhattan in New York City. 
Governors Island was a military base for over three hundred years. Fort Jay is the largest fort there. The island was made bigger by about 82 acres (33 ha) of landfill on its southern side when the first New York City Subway was excavated in the early 20th century.