Paleolithic sites are located within the Cagayan Valley Basin which is bordered by the Sierra Mountain range on the East; the Caraballo on the South; the Cordillera Central on the west; and the Babuyan Channel on the north.
Found in two municipalities of the province, namely, Solana and Penablanca, Paleolithic sites yielded the earliest stone tools and remains of extinct and extant species of animals.
Archaeological excavations undertaken in Solana and vicinities resulted in the discovery of more than 68 Paleolithic sites in the Awidon Mesa formation. These sites yielded stone tools and fossils of extinct animals that include stegodons, elephants, rhinoceros, and large tortoise. The sites tended to confirm previous reports by prominent paleontologists and archaeologists from Europe that both Pleistocene mega-fauna fossils and chopper-chopping stone tools were present in the valley, suggesting mid-Pleistocene date for tool technology in the area at the earliest and later periods.
The frontiers of prehistory is thus being broadened and pushed back. Tentative results of radio-metric reading in the valley have yielded at tektite date of approximately .92 - 1.7 m.y. The Mid-Pleistocene dating of the presence of man in the Philippines has been established.
On the eastern flank of the valley in the Municipality of Penablanca, archaeological exploration specifically in the Callao Limestone formation revealed the presence of 93 archaeological sites that yielded stone tools of Paleolithic industry and bones and shells of animals still living in the vicinities. Of these sites, 78 are caves and rock shelters. The archaeological study of the caves in the Callao limestone formation suggests post-Pleistocene sites where a Paleolithic type of technology persisted. The materials recovered indicate that the people were hunters and gatherers who exploited forest and riverine environments.
***Cagayan is undoubtedly one of the richest archaeological sites in the Philippines. Excavations by the National Museum and field research by the Cagayan Museum have yielded vast archeological findings including artifacts dating back to: the Paleolithic Age; the Neolithic Age, a time when man started to produce his own food through domestication of plants and animals; Iron Age which covers the transition from 2000 B.C. to 1000 A.D. Culture has progressed to a point where there is already knowledge of smelting and forging iron, the use of more advanced agricultural techniques, and weaving. Cagayan Valley, like many other provinces in the Philippines, was never isolated from foreign influence as was earlier believed. It was once a part of the long prehistoric international trade with neighboring countries. The Historic Age likewise chronicled the date when Juan Salcedo visited the valley. Such discoveries give a diachronic view of the technological and cultural evolution of Cagayan.
Satements of authenticity and/or integrity
The National Museum archaeologists and experts at the University of the Philippines and research institutions in several countries have been engaged in significant archaeological researches in Cagayan Valley. Their findings revealed the earliest trace of the emergence of man in the Philippines projected back in time to the middle of the Pleistocene Epoch at about 800,000 years before the present. These evidences came in the form of stone tools identified as man made. Man probably in the form of Home erectus roamed the valley at that time.
Archaeological work covering the Pleistocene and Post Pleistocene time frames in the Philippines has been intensified and is now marked with growing precision and systematics. At the present, a project entitled "The Litho-, Bio-, and Chronostratigraphy of the Fossil Mammal Bearing Deposits in the Philippines" is being implemented in close collaboration with paleontologists from the National Museum of Natural History at Leiden, the Netherlands. So far, explorations and excavations undertaken have provided evidences needed in the reconstruction of the chrono-stratigraphic framework of the fossil bearing deposits in the Philippines. Furthermore, re-excavations in the Post-Pleistocene sites associated with stone tools of Paleolithic industry have been conducted by NM archaeologists.
Comparison with other similar properties
Considerable data have been gathered on the distribution of extinct fauna and paleo-environment in Southeast Asia, such as Sulawesi, Java, Timor and Flores and the Philippines (Aziz, 1988; Fox 1971; Glover 188; Hooijer 1948, 1975; Koenigswald 1958; Shutler 1988, Sondaar 1988; de Vos 1988, Bautista 1988). The discovery of earliest evidence of the presence of mega-fauna in the Philippines has widened the knowledge of distribution of these extinct animals in Southeast Asia. Through these findings, the reconstitution of the local faunal evolution and the position of the Philippines in relation to a large scale migration pattern of vertebrates including man in Southeast Asia are known.
To protect the area for the present and future generations of Filipinos, Presidential Decree No. 1109 was passed, "Declaring the Archaeological areas in the Cagayan Valley
and Kalinga - Apayao Archaeological Reservation".