Imagine cruising through a dark, mysterious river cave surrounded by stunning limestone cliffs and lush greenery. The faint echo of water dripping off stalactites reverberates around you, and you’re gliding through quiet, ancient tunnels. This is the Puerto Princesa Underground River, one of the natural wonders of the Philippines and a UNESCO World Heritage Site. Hidden within the picturesque island of Palawan, this underground river system is a bucket-list destination for adventurers, nature lovers, and anyone who loves a good mix of mystery and beauty.

Whether you’re wondering what makes this spot so unique or planning to visit soon, this guide breaks everything down for you—from the jaw-dropping geological features to some practical tips for exploring the caves.

The Puerto Princesa Underground River is an underground river system located in the Saint Paul Mountain Range on the northern coast of Puerto Princesa, Palawan. Its official name is the Puerto Princesa Subterranean River National Park, and it’s one of the longest navigable underground rivers in the world, stretching more than 8 kilometers!

What makes it truly special is that the river runs through a massive cave system, complete with towering stalactites (the icicle-like formations hanging from the ceiling), stalagmites (rock formations that grow upward), and grand chambers that leave visitors in awe. And here's a fun fact: the underground river flows directly into the West Philippine Sea, making it a rare example of a river that mixes freshwater and saltwater.

You might be wondering why this underground river is such a big deal. Well, it’s one of those places on Earth where nature’s creativity is unmatched!

The Puerto Princesa Underground River was added to the UNESCO World Heritage list in 1999, and it’s also recognized as one of the New 7 Wonders of Nature. The combination of its unique geological structure, pristine ecosystem, and incredible biodiversity made it stand out from other natural attractions.

The national park is home to an impressive variety of plant and animal life. Inside the caves, you’ll find bats, swiftlets (tiny birds that make nests from their saliva), and even crabs that have adapted to the low-light conditions. Outside the caves, the surrounding forest acts as a sanctuary for endangered species like the Palawan peacock-pheasant and the monitor lizard.

This biodiverse haven isn’t just about caves and critters, though. The park also features ancient rainforest that perfectly complements the limestone cliffs for some of the best postcard-perfect views you’ve ever seen.

Exploring the Underground River

Getting There

The underground river is located around 80 kilometers north of Puerto Princesa City, the capital of Palawan. The most common way to reach it is by land, which takes about two hours by van or private car. Before heading into the protected national park, visitors must obtain permits from the Puerto Princesa Subterranean River National Park’s office or arrange everything through a guided tour operator.

Once you have permits, the adventure begins with a short boat ride from Sabang Beach to the mouth of the river. Pro tip: Prepare for some dazzling views along the way as you cross crystal-clear blue waters surrounded by towering cliffs and tropical vegetation.

Inside the Caves

Exploring the underground river itself is done by paddle boat, with a guide steering you through the cave system. Tours typically cover around 1.5 kilometers of the river (only specialized researchers are allowed to explore the entire stretch).

As you venture into the cave, you’ll be surrounded by otherworldly landscapes shaped over thousands of years. Some chambers are so massive that they could fit small buildings inside, while others are narrow and low-ceilinged, giving you the sensation of being deep in the heart of the Earth.

What sets this tour apart from your standard nature trips is the darkness. With only the boat’s small spotlight illuminating your path, the dramatic shadows bring the stalactites and stalagmites to life. Many formations have been named for their uncanny resemblance to objects, animals, or even people. Watch out for formations like “The Curtain,” “The Candle,” and “The Cathedral Room,” whose shapes boggle the imagination.

Don’t Forget About the Bats!

While meandering through the caves, one thing you’re sure to notice is the bats. Thousands of these nocturnal creatures live in the underground river, and you’ll hear their high-pitched squeaks as they flutter about above. Don't worry, though—they’re harmless and more likely to stay out of your way.

When Is the Best Time to Visit?

The best time to explore the underground river is during the dry season, which runs from November to May. During this time, the weather is sunny, and the waters are calmer, making it much easier to get to the river’s entrance.

The rainy season (June to October) can bring sudden downpours and sometimes even cancellations of tours due to safety concerns. If you’re planning a trip during this season, keep an eye on the weather forecast and prepare for some flexibility in your schedule.

What to Bring and Wear

Traveling to the Puerto Princesa Underground River doesn't require any specialized gear, but having the right items can make your trip more comfortable. Here’s a quick checklist:

  • Lightweight, breathable clothing (it can get humid inside the caves)
  • Sturdy sandals or water-resistant footwear
  • Sunscreen, hats, and sunglasses for the boat ride
  • A poncho or light raincoat (just in case)
  • A waterproof bag to protect your belongings from splashes

Cameras and phones are welcome, but it’s worth noting that the low-light conditions in the caves can make it tricky to take photos without flash. Pro tip: Focus less on snapping pictures and more on enjoying the experience in real-time!