MANILA—Google on Sunday put out a special doodle celebrating the 7th anniversary of the Puerto Princesa Subterranean River making the Ramsar List of Wetlands of International Importance.

The doodle features the entrance of the famous natural wonder, one of the world’s longest underground waterways at 8.2 kilometers.

The underground river made it to the New 7 Wonders of Nature in 2011. It is also a UNESCO World Heritage Site.

"Aside from celebrating the destination, we hope that this effort serves as a reminder to do our part in conserving it," Google said.