[2] From west to east, the valley is concentrated in the municipalities of Caguas, Gurabo, San Lorenzo, Juncos, Las Piedras, and Humacao.

[3] This valley is fed mainly by the Río Grande de Loíza, the largest hydrological basin in Puerto Rico, and numerous tributaries such as the Cagüitas, along which the contemporary settlement of Caguas was built.

Except for the alluvium zone, the rocks in the basin do not generate large aquifers due to their low permeability.

[1] La India Dormida (Spanish for "the sleeping Indian [woman]") is a famous geographical landmark for locals in the Valley of Caguas.

According to legend, the Taíno cacique Caguax had a niece called Taina (or Tayana) who sacrificed herself and was turned into the mountain during the Spanish conquest of Borinquen (or Boriken, the native name for Puerto Rico).