MontonesMontones is a barrio in the municipality of Las Piedras, Puerto Rico. Its population in 2010 was 9,332.HistoryMontones was in Spain's gazetteers until Puerto Rico was ceded by Spain in the aftermath of the Spanish–American War under the terms of the Treaty of Paris of 1898 and became an unincorporated territory of the United States. In 1899, the United States Department of War conducted a census of Puerto Rico. Montones was two separate barrios: Montonos Abajo had a population of 899 and Montones Arriba had a population of 937.