The most populated municipality in the Commonwealth of Puerto Rico is San Juan. With a population of 342,259 as of the 2020 census, it is the 57th-largest city under the jurisdiction of the United States. Spanish colonists established San Juan in 1521, naming it Ciudad de Puerto Rico (literally, "City of Puerto Rico," a wealthy harbor city). The city of San Juan is situated in the Northern Plains area of Puerto Rico, near the island's north-eastern coast. It is located east of Guaynabo, south of the Atlantic Ocean, north of Caguas and Trujillo Alto, and west of Carolina. A total of 76.93 square miles (199.2 km2) of land is occupied by the city, of which 29.11 square miles (75.4 km2) (37.83%) is water. San Juan Bay and the Condado and San José Lagoons are the city's two largest bodies of water. The highest point in the municipality of San Juan rises on an unidentified hill in the Morcelo district of Caimito, not far from the municipal border with Caguas, at about 1,030 feet (314 meters) above sea level.