This seven-chambered cave in Peñablanca, Cagayan boasts of massive limestones, seven skylights and a chapel. Callao cave is home to the oldest human remains ever found in the country and in Southeast Asia, thus, making Cagayan as the “Cradle of the Philip pine Civilization.” Watch the circadian flight of millions of bats at dusk, experience the “Mororan” phenomenon, kayak, and swimming or go fishing at the Pinacanauan river.