Cataño is a town and municipality on the northeastern coastal plain of Puerto Rico. It is west of the capital San Juan, east of Toa Baja, nort…Cataño is a town and municipality on the northeastern coastal plain of Puerto Rico. It is west of the capital San Juan, east of Toa Baja, north of Bayamón and Guaynabo, and south of San Juan Bay. Part of the San Juan metropolitan area, Cataño is spread over 7 barrios and the downtown area and administrative center of Cataño Pueblo. It is the smallest municipality of Puerto Rico by land area.