Puerto Princesa Subterranean River

Puerto Princesa Subterranean River National Park covers 22,202 hectares in the Saint Paul Mountain Range on the western coast of Palawan, about 80 km north of Puerto Princesa. Its centrepiece is an underground river that flows through a limestone karst cave system and into the South China Sea, set within a mountain-to-sea sequence of ecosystems^[1].

Birds are the largest vertebrate group in the park: about 165 of Palawan's 252 known bird species occur here, including all 15 of Palawan's endemic birds such as the blue-naped parrot and Palawan hornbill. About 30 mammal species are recorded, among them the long-tailed macaque, Palawan bearded pig and Palawan porcupine, along with 19 reptile species, eight of them endemic. Nine bat species and two swiftlet species live in the cave, and dugongs and hawksbill sea turtles feed in the coastal waters^[1].

The park holds 13 forest types found in tropical Asia, including lowland rainforest, limestone forest, montane forest, mangrove and beach forest. Researchers have identified more than 800 plant species, and at least 295 of the trees are dipterocarps; common lowland trees include dao, ipil and apitong^[1].

The park is a limestone karst landscape of stalactites, stalagmites and large chambers. The Puerto Princesa Subterranean River is an 8.2 km underground section of the Cabayugan River within a cave system at least 32 km long. Seawater mixes with the river's fresh water up to about 6 km inland, and Italian's Chamber, about 360 m long, is one of the largest cave rooms in the world^[1].

The park lies in the tropical lowlands of western Palawan. Heavy rain temporarily removes the layering of fresh and salt water in the underground river, so rainfall visibly changes conditions inside the cave^[1].

Sources consulted for this entry give little on the human history of the area beyond its recent management. The Puerto Princesa city government has managed the park since 1992^[1].

The park was established on 12 November 1999 and is governed by the Department of Environment and Natural Resources together with the city of Puerto Princesa. UNESCO inscribed it as a World Heritage Site on 4 December 1999 for its mountain-to-sea ecosystem, it became a Ramsar Wetland Site on 30 June 2012, and it was confirmed as one of the New7Wonders of Nature in January 2012^[1].

The main attraction is the underground river and its cave chambers, explored by boat from the shore. The cave, the surrounding forest and the coast make up the visit^[1].

Most visitors travel by road to the seaside village of Sabang, then take small paddled boats (bangkas) into the park^[1].

The park is classed as IUCN Category III (natural monument or feature) and carries three international recognitions: World Heritage Site, Ramsar wetland and New7Wonders of Nature. Its protection covers the whole sequence from mountain forest to coastal waters rather than the cave alone^[1].