Along with Magueyes, Tibes, Portugués, Maragüez, Machuelo Arriba, and Cerrillos, Montes Llanos is one of the municipality's seven rural interior barrios.

[3] Montes Llanos is a mountainous rural barrio located in the central portion of the municipality, north of the city of Ponce, at latitude 18.118717 N, and longitude -66.139594 W.[4] The toponymy, or origin of the name, is related to the old "Hato Llano" barrio.

[5] Montes Llanos is bounded on the North by PR-505 (roughly), on the South by the hills north of Pastillo Road and El Cedro I Road, on the West by the hills west of Río Chiquito, and on the East by the hills west of Río Bayagan and PR-505 (roughly).

[6][7] In terms of barrio-to-barrio boundaries, Montes Llanos is bounded in the North by Barrios San Patricio and Maragüez, in the South by Portugués and Machuelo Arriba, in the West by Tibes, and in the East by Barrio Maragüez.

[6] Barrio Montes Llanos is home to the origin of the Río Chiquito.