All I can say during the entire tour inside the underground river was “WOW”. It is amazing to think that everything inside was made by nature. The whole tour is from 7am - 4pm. This includes the van pickup from your hotel, 2hours travel by land, ALOT of waiting time in Sabang wharf, lunch, boat ride going to the island where the underground river is, ANOTHER WAITING TIME for the boat that will tour you inside the PPUR and the travel time going back to your hotel. Just please be advised that waiting time is included in your itinerary so please stay cool even if you have been waiting in Sabang wharf for almost 2 hours. In all fairness, the tour is organized, they have a recorded audio for the explanations, a souvenir card, and an earphone that you can keep after the trip.