Puerto Rico, officially the Commonwealth of Puerto Rico (P.R.), is the smallest island in the Greater Antilles in the Caribbean sea. It has a population of just under four million people and has loose political and cultural affiliations with the United States of America, which it is a territory. (TXF: "Little Green Men")
Unlike the U.S. which mostly speaks English, Puerto Rico speaks mainly Spanish and its residents are known as Puerto Ricans. (TXF: "Little Green Men")
History
A massive meteorite crater in a mountain range near the city of Arecibo has gained Puerto Rico some notoriety in the global scientific community as it is the site of the world's largest radio telescope; the Arecibo Ionospheric Observatory. Fox Mulder went there in 1994 to investigate possible evidence of contact with aliens. (TXF: "Little Green Men")