Río Piedras (Spanish pronunciation: [ˈrio ˈpjeðɾas]) (Spanish for ''stones river'') is an urbanized commercial and residential district in San Juan, the capital municipality of Puerto Rico, concentrated in the barrios of Pueblo, Universidad, Hato Rey Sur, El Cinco, and Monacillo Urbano, about 4 to 7 miles (6.4 to 11.3 km) from the Old San Juan historic quarter, Condado and Isla Verde resort areas, and SJU airport.

The area where Río Piedras is located today was previously settled by the Taíno, and archaeological sites have been uncovered nearby in Carolina.

A road connecting Río Piedras to San Juan was built during this time, along with the first church, Iglesia Nuestra Señora del Pilar, at the site of the modern town plaza.

The Camino Real, precursor to the Carretera Central, connected Río Piedras with Caguas and to southern Puerto Rico, was also built before the end of the century.

[7] The municipality of Río Piedras became part of the capital city of San Juan on July 1, 1951, after the approval of Project 177 by the House of Representatives of Puerto Rico.

[2] In July 1980, it was revealed by then Mayor Hernán Padilla, that Calle De Diego, one of the roads with the greatest commercial movement and traffic congestion in Río Piedras, would be converted into a Pedestrian Walkway in the following year.

Padilla indicated that the construction of the Pedestrian Walkway, which would extend from the street Ferrocarril to Ponce de Leon Avenue, including a portion of Calle del Carmen, would cost around $1.5 million.

It would have two ornamental fountains, four clocks, attractive light fixtures, and 42 trees that would complement the appearance of Paseo De Diego, which had all the details of a mall, but outdoors.

The Puerto Rico Department of Corrections and Rehabilitation operates the Hogar Intermedio para Mujeres in Río Piedras, which opened in 1996.

The Río Piedras Plaza del Mercado (the old marketplace) is the largest of its kind on the island and features a series of shops that offer goods and services, and it is also popular with students of the university.