The Caguas Valley (

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ...

: ''Valle de Caguas''), or the Caguas-Juncos Valley, and popularly referred to as the Turabo Valley (''Valle del Turabo''), is a large valley lying between two mountain subranges of the

Cordillera Central Central Cordillera refers to the New Guinea Highlands. Cordillera Central, meaning ''central range'' in Spanish, may refer to the following mountain ranges: * Cordillera Central, Andes (disambiguation), several mountain ranges in South America ** ...

Sierra de Cayey The Sierra de Cayey ( English: "Cayey Mountains") is one of three subranges of the Cordillera Central mountain range in the main island of Puerto Rico. It is demarcated from the eponymous main subrange of ''Cordillera Central'' by the San Crist� ...

and Sierra de Luquillo, in the eastern region of the main island of

Puerto Rico ; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territo ...

. From west to east, the valley is concentrated in the municipalities of

Caguas Caguas (, ) is a city and municipality in central eastern Puerto Rico. Located in the eponymous Caguas Valley between the Sierra de Cayey and Sierra de Luquillo of the Central Mountain Range, it is bordered by San Juan and Trujillo Alto to ...

, Gurabo, San Lorenzo, Juncos, Las Piedras, and

Humacao Humacao () is a city and municipality in Puerto Rico located in the eastern coast of the island, north of Yabucoa; south of Naguabo; east of Las Piedras; and west of Vieques Passage. Humacao is spread over 12 barrios and Humacao Pueblo (the ...

Topography_of_the_Commonwealth_of_Puerto_Rico_by_USDA

Geography

In a clockwise direction, the valley is bound by the ''Altos de La Mesa'' and '' Altos de San Luis'' mountain ridges to the north, the Sierra de Luquillo in the northeast, the San Lorenzo Batholith in the east and southeast, the

in the south, and the foothills of the ''

'' in the west. This valley is fed mainly by the

Río Grande de Loíza The Rio Grande de Loíza (English language, English: ''Great River of Loíza'' or ''Loíza River'') is a river in the Geography of Puerto Rico, main island of Puerto Rico. It is the largest river in Puerto Rico by discharge volume. Situated on th ...

, the largest hydrological basin in Puerto Rico, and numerous tributaries such as the Cagüitas, along which the contemporary settlement of

was built. The name Valle del Turabo ("Turabo Valley") comes from the Turabo River, which is another tributary that flows from the south. The Gurabo River, another major tributary, feeds into the Grande de Loíza at a region where the valley narrows into a

rift valley A rift valley is a linear shaped lowland between several highlands or mountain ranges produced by the action of a geologic rift. Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear ...

, often called the Gurabo Valley, that runs from west to east and ends in Las Piedras and

in the southeastern coast of the island.

Geology

The Caguas Valley, from

to Juncos, is formed by

Holocene The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...

alluvial deposits that lay on top of hardened rock of

volcanic A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often fo ...

origin,

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

, and intrusive and

metamorphic rocks Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...

that date from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

to the

Tertiary Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to: * Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago * Tertiary (chemistry), a term describing bonding patterns in organic ch ...

period. There are also small deposits of limestone. Except for the alluvium zone, the rocks in the basin do not generate large

aquifers An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...

due to their low permeability. The alluvium in the valley includes non-uniform mixtures of

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...

and

mud Mud (, or Middle Dutch) is loam, silt or clay mixed with water. Mud is usually formed after rainfall or near water sources. Ancient mud deposits hardened over geological time to form sedimentary rock such as shale or mudstone (generally cal ...

, varying in thickness from 0 feet in with consolidated rocks to 160 feet in Caguas and Gurabo. In the area towards Gurabo and Juncos the alluvium contains more sand and gravel than in the area of Caguas; these alluvial deposits form the main aquifer in the area. The flows of the Loíza River and its tributaries, mainly the Gurabo River, have eroded most alluvial deposits within the fluvial flood zones.

Climate

The climate of the Caguas-Juncos Valley is rainy, with areas receiving up to 100 inches of precipitation annually. Rain varies throughout the year with the dry period lasting from January to April, the rainiest period being from May to June, the driest period from July to August, and the period of heavy rains lasting until the end of the year.

''La India Dormida''

''La India Dormida'' (Spanish for "the sleeping Indian

oman Oman, officially the Sultanate of Oman, is a country located on the southeastern coast of the Arabian Peninsula in West Asia and the Middle East. It shares land borders with Saudi Arabia, the United Arab Emirates, and Yemen. Oman’s coastline ...

) is a famous geographical landmark for locals in the Valley of Caguas. Although often called a mountain, this is actually a group of mountains that through

forced perspective Forced perspective is a technique that employs optical illusion to make an object appear farther away, closer, larger or smaller than it actually is. It manipulates human visual perception through the use of scaled objects and the correlation bet ...

(when seen from the north) form the shape of a sleeping woman. According to legend, the

Taíno The Taíno are the Indigenous peoples of the Caribbean, Indigenous peoples of the Greater Antilles and surrounding islands. At the time of European contact in the late 15th century, they were the principal inhabitants of most of what is now The ...

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). The best way to observe this optical illusion is from Altos de San Luis, Altos de La Mesa and on expressway

PR-52 Puerto Rico Highway 52 (PR-52), a major toll road in Puerto Rico, is also known as . It was formerly called . It runs from PR-1 in southwest Río Piedras and heads south until it intersects with highway PR-2 in Ponce. At its north end, the sh ...

and highway PR-1 when driving from north to south through the valley.