- Also known as St. Paul’s Subterranean River
- Located in the Saint Paul Mountain range in the Phillipines
- An 8.2 km navigable underground river
- Longest underground river in Asia and second longest in the world
The Puerto Princesa Subterranean River is the longest underground river in Asia and the second longest underground river in the world. It features an ## feet (8.2 km) navigable underground river that travels through the cave before flowing into the South China Sea. The Puerto Princesa Subterranean River travels through a cave that features stalactites, stalagmites, and many large chambers. The park area encompasses a complete sea to mountain ecosystem and features 8 of the 13 different forest types found in Asia. Collectively there are over 800 different plant species.