The caves offer a remarkable spectacle at dusk when thousands of bats emerge from the caverns' mouths and blot out the remaining light in the sky at daytime, spelunkers get the chance of finding new chambers. Out of the hundreds, only seven so far have been explored. Callao's unique attraction however is the Gothic chapel of stalactite and stalagmite spires and arches complete with a stone altar and pew. It is lit from above by natural skylight. In the caves of Mount Banahaw in Southern Luzon, natives say they can communicate with the supernatural within the chambers.
Visitors are likely to be treated to accounts of the legends behind each inner chamber.
Among the attractions of the Saint Paul National Park in Palawan are its caves which shelter an underground river. The finds are believed to have existed during the Ice Age more than 20,000 years ago.