Bayamón is a city and municipality on the northern coastal plain of Puerto Rico, part of the San Juan–Bayamón–Caguas metropolitan area. With roughly 185,000 residents, it is the island's second-most populous municipality after San Juan. The municipality is bounded by Guaynabo to the east, Toa Alta and Naranjito to the west, Toa Baja and Cataño to the north, and Aguas Buenas and Comerío to the south, and it is organized into 12 barrios plus the downtown district of Bayamón Pueblo. Founded in 1772, Bayamón developed first as an agricultural community, with an economy built on sugarcane, tobacco, coffee, and livestock along the Río Bayamón. In the early twentieth century, the expansion of sugar mills brought industrial employment, and the municipality eventually grew into one of the island's principal urban centers. That layered history is still visible in its mix of colonial-era streets, mid-century neighborhoods, and modern commercial development. Today Bayamón functions as a major residential and economic hub within the San Juan metro. It is home to the Parque de las Ciencias, a science-themed park set among karstic hills, and to the Coliseo Rubén Rodríguez, an indoor arena that hosts the Vaqueros de Bayamón basketball franchise and other major events. Higher education is a defining presence, with a University of Puerto Rico campus known for its School of Optometry, Bayamón Central University, the American University of Puerto Rico, and the Universidad Central del Caribe among its institutions. Transportation links Bayamón tightly to the capital. The Tren Urbano rapid transit line serves San Juan, Guaynabo, and Bayamón with a single 10.7-mile, 16-station line, giving residents rail access to the metro area's employment and cultural centers. Combined with the island's road network and its central location, Bayamón offers urban convenience, established neighborhoods, and a strong sense of municipal identity.