Carolina, Puerto Rico in the context of "Loíza, Puerto Rico"

The San Juan–Bayamón–Caguas metropolitan area, most commonly known as the San Juan metropolitan area (Spanish: área metropolitana de San Juan), is the largest and most populous metropolitan statistical area (MSA) in Puerto Rico, concentrated in the capital municipality of San Juan and surrounding municipalities, including Bayamón, Caguas, and Carolina, on the northeastern coastal plain of the main island. One of 6 metropolitan statistical areas in Puerto Rico, it is within the San Juan–Bayamón combined statistical area (CSA), which is one of 3 primary statistical areas in the archipelago as defined by the United States Census Bureau. As of 2023, the estimated population of the San Juan–Bayamón–Caguas metropolitan area is 842,535 in municipalities in the conurbation and 1,193,198 in municipalities outside the urban core, making it the fourth largest in the insular Caribbean.

Trujillo Alto (Spanish pronunciation: [tɾuˈxiʝo ˈalto]) is a town and municipality of Puerto Rico. Located on the northeastern coastal plain on the boundary between the Northern Karst Belt and Sierra de Luquillo, it is north of Caguas and Gurabo, southeast of San Juan, and west of Carolina. Its geography features river lowlands and mountains. Part of the San Juan metropolitan area, Trujillo Alto is spread over 6 barrios and the downtown area and administrative center of Trujillo Alto Pueblo.

Trujillo Alto was officially founded in 1801, but gained more importance during the 20th century. Due to its proximity to the capital, San Juan, the city has become a suburb of the metropolitan area, which has sparked its growth during recent years. The population of Trujillo Alto has increased through the last century from 9,576 (1930) to 74,482 (2010). According to the 2010 Census, it is Puerto Rico's tenth-most populated municipality. The urban setting of Trujillo Alto is compact, being divided into the barrios Carraízo, Cuevas, Dos Bocas, La Gloria, Quebrada Grande, Quebrada Negrito, Saint Just and Pueblo.

Gurabo (Spanish pronunciation: [ɡuˈɾaβo]) is a town and municipality in eastern Puerto Rico. It is located in the central eastern region, north of San Lorenzo; south of Trujillo Alto; east of Caguas; and west of Carolina and Juncos. Gurabo is spread over 9 barrios and Gurabo Pueblo (the downtown area and the administrative center of the city). It is part of the San Juan-Caguas-Guaynabo Metropolitan Statistical Area.

Carolina barrio-pueblo is a barrio and the administrative center (seat) of Carolina, a municipality of Puerto Rico. Its population in 2010 was 1,201.

As was customary in Spain, in Puerto Rico, the municipality has a barrio called pueblo which contains a central plaza, the municipal buildings (city hall), and a Catholic church. Fiestas patronales (patron saint festivals) are held in the central plaza every year.

Juncos (Spanish pronunciation: [ˈxuŋkos]) is a town and one of the 78 municipalities of Puerto Rico. It is located in the eastern central region of the island to the west of the Caguas Valley, south of Canóvanas and Carolina; southeast of Gurabo; east of San Lorenzo; and west of Las Piedras. Juncos is spread over 9 barrios and Juncos barrio-pueblo (the downtown area and administrative center of the city). It is part of the San Juan-Caguas-Guaynabo Metropolitan Statistical Area.

Juncos was founded on the request of Tomás Pizarro on August 2, 1797, having previously been a village which evolved from a small ranch, the Hatillo de los Juncos. This ranch was part of the Hato del Valenciano, which gave its name to the Río Valenciano which bisects the city before joining the Río Gurabo to the north of the settlement.

Canóvanas (Spanish pronunciation: [kaˈnoβanas], locally [kaˈnoβanaʔ]) is a town and municipality in Puerto Rico, located in the northeastern region, north of Juncos and Las Piedras; south of Loíza; east of Carolina; and west of Río Grande. Canóvanas is spread over 6 barrios and Canóvanas Pueblo (the downtown area and administrative center). It is part of the San Juan-Caguas-Guaynabo Metropolitan Statistical Area.