Get an early start on the day with pickup from your hotel in Puerto Princesa, then begin the scenic drive to Sabang, the jumping-off point for Puerto Princesa Subterranean River National Park.
Upon arrival in Sabang, transfer to a small motorized boat for the trip to Entrance Beach, where you can watch for monitor lizards and macaques at the edge of the thick forest (bird lovers should keep their eyes out for some of the 165 species that have been recorded in the park). From there, continue onto the underground river on a paddle boat, slipping through pitch-black caverns for 5 miles (8 kilometers). Spot stalactites and stalagmites and listen to the sounds of the swifts and bats that live inside the cave system.
When you emerge out the other side, return to Sabang port for a buffet lunch at a local restaurant. This full-day tour concludes with the return drive to Puerto Princesa City, and drop-off at your hotel.