Puerto Rico is a place.
Puerto Rico ( Spanish for `` Rich Port '' ) , officially the Commonwealth of Puerto Rico ( Estado Libre Asociado de Puerto Rico , `` Free Associated State of Puerto Rico '' ) and briefly called Porto Rico , is an unincorporated territory of the United States located in the northeast Caribbean Sea . It is an archipelago that includes the main island of Puerto Rico and a number of smaller ones such as Mona , Culebra , and Vieques . The capital and most populous city is San Juan . The island 's population is approximately 3.4 million . Puerto Rico is the capital city of the , in the Misiones Province of Argentina .