The presence of sedimentary rock formations in the different parts of the Philippines has been the main reason for the discovery a larger number of caves in the country. Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it filtered through the soil turns it into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.
In recognition of the importance of Philippine caves and the need for their protection, Republic Act No. 9072 or the National Caves and Cave Resources Management and Protection Act was enacted last April 8,2001.
RA 9072 defines caves as “any naturally occurring void, cavity, recess or system of interconnected passages beneath the surface of the earth or within a cliff or ledge and which is large enough to permit an individual to enter, whether or not the entrance, located either in private or public land, is naturally formed or man-made. It shall include any natural pit, sinkhole or other feature which is an extension of the entrance”.
Caves are considered unique, natural and non-renewable resources with important scientific, economic, educational, cultural, historical and aesthetic values. They are home to specialized mineral formations with unique and diverse flora and fauna.
Caves are characterized by the following specialized mineral formations known as Speleothems and Speleogens:
- Stalactite or dripstone – is a type of speleothem that hangs from the ceiling or wall of limestone caves formed from the deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions.
- Stalagmite – is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings.
- Cave Scallops – dish-shaped depressions formed by eddies in flowing water against cave walls, floors and ceilings
- Anastomoses – are erosional forms of micro-relief in caves and represent one of the earliest stages of speleogenesis.
Class I : Caves with delicate and fragile geological formations, threatened species, archaeological and paleontological values, and extremely hazardous conditions.
Allowable use may include mapping,photography, educational and scientific purposes.
Class II : Caves with areas or portions that have hazardous conditions and contain sensitive geological, biological,archaeological, cultural, historical values, or high quality ecosystem.
It may be necessary to close sections of these caves seasonally or permanently. It is only open to experienced cavers or guided educational tours/visits.
Class III : Caves generally safe to inexperienced visitors, with no known threatened species, archaeological, geological, cultural and historical values. These caves can also be utilized for economic purposes such as guano extraction and edible birds nest collection.
Prohibited acts in caves Pursuant to Section 7 of the Cave Act:
- Knowingly destroying, disturbing, defacing, marring, altering, removing, or harming the speleogen or speleothem of any cave or altering the free movement of any animal or plant life into or out of any cave.
- Gathering, collecting, possessing, consuming,selling,bantering or exchanging or offering for sale without authority any cave resource
- Counseling, procuring, soliciting, or employing any other person to violate any provision of the Cave Act.
Atlas of Philippine Inland Wetlands and Classified Caves (1st Edition, 2016)