San Juan is the capital city of Puerto Rico.

San Juan is one of the most populous municipalities in the Commonwealth of Puerto Rico, an unincorporated territory of the United States. As of the 2010 census, it is the 46th-largest city under the jurisdiction of the United States, with a population of 395,326. San Juan was founded by Spanish colonists in 1521, who called it Ciudad de Puerto Rico ("The City of Puerto Rico", Spanish for a rich port city).