Puerto Rico is a piece of land surrounded by water.
An archipelago ( [ ɑːrkᵻˈpɛləɡoʊ ] ) , sometimes called an island group or island chain , is a chain , cluster or collection of islands . 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 .