Trujillo Alto

 city, village, municipality

Trujillo Alto is a municipality of Puerto Rico located in the Northern Coastal Plain and in the karst zone, north of Caguas,and Gurabo; southeast of San Juan, and west of Carolina. Trujillo Alto is part of the San Juan Metropolitan Area, which includes the municipalities of Bayamón, Guaynabo, Cataño, and Toa Baja. The city is spread over 6 wards and Trujillo Alto Pueblo (The downtown area and the administrative center of the city). It is part of the San Juan-Caguas-Guaynabo Metropolitan Statistical Area.

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 largest municipality by population.

In 1953-54, the Carraízo hydroelectric dam was constructed in Trujillo Alto by the Sumner Sollitt Construction Company of Chicago, under contract by the Puerto Rico Water Resources Authority. The dam forms the Loíza Lake, a reservoir which serves as the main source of the water supply for San Juan, Puerto Rico.