Presents the results yielded by two expeditions who targeted previously untouched caving areas in the Philippines: the mountainous karsts of Sultanat Kudarat and Kalinga provinces as well as the coastal cone karst of Sta. Teresita. Sixty-nine caves with a total of about 12.5 km of passages are described in detail. Includes area maps and an in-depth chapter on the biospeleology of Luzon Island.