Puerto Princesa Underground River (UNESCO)

The Puerto Princesa Subterranean River National Park is home to the world's longest navigable underground river — 8.2 kilometers winding through a vast cave system beneath St. Paul Mountain. A UNESCO World Heritage Site since 1999 and one of the "New Seven Wonders of Nature" since 2012.

The boat ride covers the first 4.3 kilometers of the cave. The audio guide (on the boat) explains the gigantic stalactites and stalagmites that have grown over millions of years — some several stories high. The cave houses a huge colony of bats and swallows, whose sounds echo surreally in the darkness. The play of flashlights on the limestone formations creates bizarre shadow images — you can see cathedrals, faces, mushrooms, and entire landscapes.

The journey from Puerto Princesa city takes 1.5 hours to the port in Sabang, then 20 minutes by Bangka boat to the cave entrance. The entire excursion takes a whole day. The number of visitors is limited to 900 per day — a permit must be booked in advance at the City Tourism Office or through a hotel/tour operator.

Puerto Princesa itself is the capital of Palawan and a pleasant town: Clean, safe, with good restaurants and the lively Baywalk (waterfront promenade) for evening strolls. Tours to Honda Bay (island hopping with snorkeling) and onward travel to El Nido by van (5–6 hours) also start from here.