Dec 3, 2023 · Capital: San Juan. Area: 3,515 sq mi (9,104 sq km). Population: ~ 3,190,000. Largest cities: San Juan, Bayamón, Carolina, Ponce, Caguas, Guaynabo, Arecibo, Toa Baja, Mayagüez, Juana Díaz, Trujillo Alto, Toa Alta, Aguadilla, Vega Baja, Humacao, Río Grande, Cabo Rojo. Official language: Spanish, English.