Rikers Island is a 413.17-acre (1.67 km2) island in the East River between Queens and the Bronx that is home to New York City's main jail complex. Supposedly named after Abraham Rycken, who bought the island in 1664, the island was originally under 100 acres (40 ha) in size, but has since grown to more than 400 acres (160 ha). The first stages of expansion were accomplished largely by convict labor hauling in ashes for landfill. The island is politically part of the Bronx, although bridge access is from Queens. It is part of Queens Community Board 1 and uses an East Elmhurst, Queens, ZIP Code of 11370 for mail.