Callao Cave is one of Cagayan province's best known tourist attractions. It has 7 chambers and 3-4 crevices which allow natural light into the caves. Located in a remote place in Penablanca town (30 minutes+ from Tuguegarao City), it has been featured and included on the DOT websites and ads. I knew the place was beautiful based from internet photos and from ads, but being there was more than an awesome experience.
To get there, we hired a tricycle en-route to Penablanca from Tuguegarao for P400.00 round-trip. Before reaching the cave, one can try the Pinacanauan river ride and pay a little extra. But we opted not to take the ride because the weather is not permitting, instead we took the road going directly near the entrance of the cave. Callao Cave is very easy to explore but requires little test of endurance as you go up the stair with close to 200 steps before witnessing the massive limestone and rock formations inside.
I observed that Callao Cave is not that popular to tourists (both local and foreign) as compared to the other northern Philippines destinations. Maybe it's because of the remote location. And there's not much to see in Cagayan than in Ilocos or the Mountain Province.