Puerto Princesa Subterranean River National Park, Philippines

The Puerto Princesa Subterranean River National Park is located about 50 kilometres (30 mi) north of the city centre of Puerto Princesa, Palawan, Philippines. The river is also called Puerto Princesa Underground River. The national park is located in the Saint Paul Mountain Range on the northern coast of the island. It is bordered by St. Paul Bay to the north and the Babuyan River to the east. The City Government of Puerto Princesa has managed the National Park since 1992. The park is also known as St. Paul's Subterranean River National Park, or St. Paul Underground River. The entrance to the Subterranean River is a short hike from the town of Sabang.

In 2010, a group of environmentalists and geologists discovered that the underground river has a second floor, which means that there are small waterfalls inside the cave. They also found a huge cave dome, measuring 300 meters above the underground river, incredible rock formations, large bats, a deep water hole in the river, more river channels, another deep cave, marine creatures, and more. Deeper areas of the underground river are almost impossible to expedite due to oxygen deprivation.
On November 11, 2011, Puerto Princesa Underground River was provisionally chosen as one of the New7Wonders of Nature. This selection was officially confirmed on January 28, 2012.


The park has a limestone karst mountain landscape. The main attraction here is St. Pauls Underground River Cave - a more than 24 km long cave, which contains an 8.2-kilometer-long underground section of Cabayugan River. A distinguishing feature of the river is that it winds through the cave before flowing directly into the South China Sea, and is navigable with a boat up to 4 kilometres in from the sea. The cave includes major formations of stalactites and stalagmites, and several large chambers, including the 360-meter-long Italian's Chamber with approximate 2.5 million square meters volume - one of the largest cave rooms in the world. The lower portion of the river up to 6 km from the sea, is subject to tidal influences. Until the 2007 discovery of an underground river in Mexico's Yucatán Peninsula, the Puerto Princesa Subterranean River was reputed to be the world's longest underground river.
The area also represents a habitat for biodiversity conservation. The site contains a full mountain-to-the-sea ecosystem and has some of the most important forests in Asia. It was inscribed by UNESCO as a World Heritage Site on December 4, 1999.