High Quality Content by WIKIPEDIA articles! Río Grande (Spanish pronunciation: ) is a municipality of Puerto Rico located in the Northern Coastal Valley, North of Las Piedras, Naguabo and Ceiba; east of Loíza and Canóvanas and west of Luquillo. Río Grande is spread over eight wards and Río Grande Pueblo (The downtown area and the administrative center of the city). It is part of the San Juan-Caguas-Guaynabo Metropolitan Statistical Area.