Underground River

 

Normally river means source of water from some hill or mountain, flow on ground and finally fall in to sea or meet with other rivers. But there is river in Philippine which follow through underground and it is called underground River.         

In 2010, a group of environmentalists and geologists discovered that the underground river has a second floor, which means that there are small waterfalls inside the cave. They also found a huge cave dome, measuring 300 meters above the underground river, incredible rock formations, large bats, a deep water hole in the river, more river channels, another deep cave, marine creatures, and more. And because it's very dark inside and very hard to get oxygen, it's dangerous for humans, so they didn't uncover all of the mysteries of this deep underground river.
On November 11, 2011, Puerto Princesa Underground River was provisionally chosen as one of the New7Wonders of Nature. This selection was officially confirmed on January 28, 2012.