I had a hard time pronouncing Pinacanauan River. When I first told a friend about it, I simply described the experience as, "Like a scene straight out of a Stephen King novel, where millions of bats flew out of the cave, completely covering the dusk sky with darkness."

There are many massive cave systems hidden within the town of Peñablanca in Cagayan Valley. The most famous of these is Callao Cave. Another cave worth visiting nearby is the Sierra Cave—a network somewhat similar to the spelunking caves of Sagada, where one has to twist and contort their body to squeeze through tight openings. This stands in stark contrast to the absolute vastness of Callao Cave, which boasts a huge underground dwelling with a cathedral-like entrance as wide as the gates of a Gothic palace.