The Puerto Princesa Subterranean River National Park is a protected area in the Philippines. It is located in the Saint Paul Mountain Range on the western coast of the island of Palawan, about 80 kilometers (50 miles) north of the city of Puerto Princesa. The park includes the Puerto Princesa Subterranean River, also called the Puerto Princesa Underground River or simply the Underground River. The park has been managed by the Puerto Princesa city government since 1992.

It was listed as a UNESCO World Heritage Site in 1999 and named one of the New 7 Wonders of Nature in 2012. It also became a Ramsar Wetland Site in 2012.

The park is a major tourist destination. Most visitors reach it by road trip to the seaside village of Sabang, where they take a Bangka, a small boat similar to a kayak, to enter the park.

History

In 2010, a group of environmentalists and geologists found that the underground river has a second level, which includes small waterfalls inside the cave. They also discovered a cave dome 300 meters (980 feet) above the underground river, rock formations, large bats, a deep water hole in the river, additional river channels, another deep cave, and marine creatures. Deeper parts of the underground river are very difficult to explore because there is not enough oxygen.

On November 11, 2011, the Puerto Princesa Underground River was temporarily selected as one of the New 7 Wonders of Nature. This selection was officially confirmed on January 28, 2012.

Geography

The Puerto Princesa Subterranean River is the second-longest underground river in the world. It includes an 8.2 km (5.1 mi) section of the Cabayugan River that flows through a cave system at least 32 km (20 mi) long. The river moves through the caves before entering the South China Sea. Saltwater mixes with freshwater up to about 6 km (3.7 mi) inside the caves. This creates layers of water, with the freshwater layer being only a few centimeters thick. During heavy rain, flooding removes the seawater, and the layers disappear. Boats can travel up to 4.3 km (2.7 mi) from the sea into the river.

The area has a limestone karst mountain landscape, which forms caves and includes large formations such as stalactites and stalagmites. One large chamber, called Italian's Chamber, is 360 meters (1,180 feet) long and has a volume of about 2.5 million square meters. It is one of the largest cave rooms in the world. Before the discovery of an underground river in Mexico’s Yucatán Peninsula in 2007, the Puerto Princesa Subterranean River was considered the longest underground river in the world.

The area supports a wide variety of plants and animals. It includes a complete ecosystem from mountain to sea and has some of Asia’s most important forests. UNESCO added the site to its list of World Heritage Sites on December 4, 1999.

Flora

The park has many different types of forests, including thirteen kinds found in tropical Asia. These include forests growing on ultramafic soils, forests on limestone soils, montane forests, freshwater swamp forests, lowland evergreen tropical rainforests, riverine forests, beach forests, and mangrove forests. Researchers have found more than 800 plant species. These plants belong to 300 different genera and 100 families. At least 295 of these plants are trees, mostly dipterocarp species. In the lowland forest, large trees such as dao (Dracontomelon dao), ipil (Intsia bijuga), dita (Alstonia scholaris), amugis (Koordersiodendron pinnatum), and apitong (Dipterocarpus gracilis) are common. Beach forest plants include bitaog (Calophyllum inophyllum), Pongamia pinnata, and Erynthia orientalis. Other plants found in the area are almaciga (Agathis philippinensis), kamagong (Diospyros pulganensis), pandan (Pandanus sp.), anibong, and rattan (Calamus sp.).

Fauna

Birds make up the largest group of vertebrates in the park. Out of 252 bird species known to live in Palawan, 165 species have been recorded in the park. This number equals 67% of all bird species in Palawan and includes all 15 bird species that are found only in Palawan. Some of the birds seen in the park include the blue-naped parrot (Tanygnathus lucionensis), Tabon scrub fowl (Megapodius cumunigii), hill myna (Gracula religiosa), Palawan hornbill (Anthracoceros marchei), and white-breasted sea eagle (Haliaeetus leucogaster).

There are about 30 mammal species recorded in the park. The long-tailed macaque (Macaca fascicularis), the only primate in the area, is often seen in the forest canopy and along shorelines during low tide. Other mammals include the Palawan bearded pig (Sus ahoenobarbus), bearcat (Arctictis binturong), Palawan stink badger (Mydaus marchei), and Palawan porcupine (Hystrix pumila).

Nineteen reptile species have been identified in the park, eight of which are found only in Palawan. Common reptiles include the common reticulated python (Python reticulatus), monitor lizard (Varanus salvator), and green crested lizard (Bronchocoela cristatella). Ten amphibian species live in the area, with the Philippine woodland frog (Rana acanthi) being the most commonly seen. One amphibian species, Barbourula busuangensis, is found only in Palawan and has been observed in the park.

Nine bat species, two swiftlet species, and a whip spider (Stygophrynus sp.) are found in the caves of the park. In coastal areas, the sea cow (Dugong dugon) and hawksbill sea turtle (Chelonia mydas) are seen feeding.

International reception

Puerto Princesa Underground River was chosen as the Philippines' entry and won the first round of voting in the New 7 Wonders of Nature competition. On July 29, 2011, after the second round of voting, it became one of 28 finalists. Mayor Edward S. Hagedorn thanked everyone who supported and voted for the Puerto Princesa Underground River (PPUR). On November 11, 2011, it was temporarily selected as one of the New7Wonders, along with the Amazon rainforest, Halong Bay, Iguazu Falls, Jeju Island, Komodo Island, and Table Mountain.

On January 28, 2012, Malacañang announced the official inclusion of the Puerto Princesa Underground River in the world's New Seven Wonders of Nature. "Confirming that the Puerto Princesa Underground River is one of the New Seven Wonders of Nature is good news," said Presidential Spokesperson Edwin Lacierda. "Filipinos from all backgrounds worked hard to support this campaign."

The Department of Tourism spokesman, Assistant Secretary Benito Bengzon Jr., stated that the underground estuary was included in the New Seven Wonders of Nature after a review process by the New7Wonders Foundation. Some people criticized the voting process, especially how voting was done in the Philippines. The rules did not stop people from voting multiple times, which made the results influenced by government and tourism campaigns encouraging frequent voting for local sites to boost tourism.

Philippine President Benigno Simeon Aquino III, during the official announcement of the Puerto Princesa Underground River as one of the 28 finalists, asked the country's 80 million cellphone users to vote for PPUR by sending text messages.

On June 30, 2019, Puerto Princesa Underground River was celebrated with a Google Doodle.