Puerto Princesa Subterranean River

The site is a protected area situated within the Saint Paul Mountain Range and features an 8.2-kilometer long underground river, recognized as one of the world's longest navigable subterranean rivers. This river flows through a spectacular limestone karst landscape before emptying directly into the South China Sea.

Designated as a UNESCO World Heritage Site and a Ramsar site, the park protects a significant biodiversity conservation area. The landscape encompasses a complete mountain-to-sea ecosystem, including some of the most important forests in Asia. The subterranean system contains unique rock formations and supports diverse wildlife within its cave environment.

Exploration of the navigable sections is conducted via paddle boat tours. The area was officially inscribed as a UNESCO site in 1999 and is recognized as one of the New 7 Wonders of Nature.