Something strange happens on the Philippine island of Palawan when the Cabayugan River reaches the 1,000-meter (3,280.8-feet) high limestone mountain called Saint Paul: the flowing water vanishes under the earth. Today’s Doodle celebrates the Puerto Princesa Subterranean River National Park, a Philippines National Park and UNESCO World Heritage Site protected by the Ramsar Convention on this day in 2012.

An international body created for the conservation of important wetlands, Ramsar designated this underground river as “unique in the biogeographic region because it connects a range of important ecosystems from the mountain-to-the-sea, including a limestone karst landscape with a complex cave system, mangrove forests, lowland evergreen tropical rainforests, and freshwater swamps.”

The river is one of the world’s longest underground waterways at 8.2-kilometers (5.1-miles)—and one of the few that flows into the sea, creating the largest subterranean estuary in the world. Small boats carry sightseers underground to marvel at dramatic stalactite and stalagmite formations.

The 24-kilometer (14.9-mile) matrix of caves—including the 360-meter (1181.1-feet) long, 80-meter (262.5-feet) high Italian’s Chamber, one of the largest cave halls in the world—is home to some 800 plant species as well as many animals found nowhere else, including giant spiders, crabs, fish, and snakes, as well as bats, swallows, and fossils dating back millions of years. The critically endangered Philippine cockatoo and Hawksbill turtle, and the endangered Green sea turtle and Nordmann’s greenshank are just a few of the protected species who survive in this one-of-a-kind habitat.

 

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Drafts by artist David Lu