At long last the authorities are starting to realize the Jagna has a rich cultural heritage after all. When the Jagna Culture and Arts Council, JCAC, decided to put up a commemorative book, the first chapter was about the pre Hispanic past. A writer contended that Jagna was already an organized community with its culture and traditions. Although the ancient folks left no written records or permanent structures except stone hedges, the practice of secondary burial could be found.

Survey of the probable burial grounds by the writers of the commemorative book located some of them. One was in Cantagay and another Canupao point. Both were found in grottos or small caves. Both areas were vandalized. In Cantagay, a coffin was thrown out of the grotto and the bones were scattered. There was an evidence treasure hunting nearby. In Canupao where there was abundance of old bones, none are found now.

There are stories of other gravesites in Jagna. One is in Larapan, another in Odiong. At present JCAC writers are trying to locate a burial ground in Cansanga. Here may be other sites and hopefully, they have not yet been vandalized. The characteristics of burial grounds are they are found in small caves beneath cliffs. Most are almost inaccessible. Coffins for adults and infants may be found. Several skeletons occupy one coffin. Ceramic shards are usually found around the coffins.

Anthropologists say that those graves are evidences of secondary burial. Recent dead are buried in shallow graves then are exhumed after several years then placed in boat shaped coffins in small caves. The practice is almost similar to those to the mountain people of Luzon . They mummify their dead by smoking the cadaver then buried in almost inaccessible places like cliffs.

If several burial grounds are found farther inland, it means that Jagna was already a thriving community before the Spaniards came. There was already a division of labor like farmers and fishermen, craftsmen like carpenters and weavers as well as traders. That means we did not just come down from the trees.

JCAC writers had collected pieces of old bones and coffin splinters in such sites to have them carbon dated to determine their age. All living beings, plant or animal, absorb carbon during their lifetime. The absorption ceases when the creature dies. Along with the common carbon, a carbon isotope called Carbon 14 is also absorbed. Carbon 14 is radioactive, which means it radiates energy and while it radiates, it also deteriorates into another form of carbon.

The half-life of Carbon 14 is 5,730 years, which means a mass of Carbon 14 becomes one half after 5,730 years. Then this mass becomes half in another 5,730 years. The limit of Carbon 14 dating is 50,000 years. A margin of error is established at 300 years. A rough analogy may be made like thus. A kilogram of ice will melt in half if left under room temperature says 32 degrees Centigrade in thirty minutes.

If a kilogram block of ice left in a room 32 degrees warm weighs one half kilogram afterward, this means the block is in the room thirty minutes. If the same block weighs one-fourth kilogram, it mean the block is there for one hour. If the block weighs one-eighth kilogram later, it means it had been there for an hour and thirty minutes and so on.