title: Rikers Island
context: Rikers Island (/ˈraɪkərz/) is New York City's main jail complex,[1] as well as the name of the 413.17-acre (167.204ha) island on which it sits, in the East River between Queens and the mainland Bronx, adjacent to the runways of LaGuardia Airport.[2] Supposedly named after Abraham Rycken[3][4] who bought the island in 1664,[5] the island is home to one of the world's largest correctional institutions and mental institutions[6] and has been described as New York's most famous jail.[7] The island was originally under 100 acres (40ha) in size, but has since grown over four times to more than 400 acres (160ha). Much of the first stages of expansion was accomplished by convict labor hauling in ashes for landfill. The island itself is politically part of the Bronx, though it is included as part of Queens Community Board 1 and has a Queens ZIP Code of 11370.[8]
question: What is the worlds largest prison?
answers: Rikers Island