Puerto Princesa Subterranean River

Puerto Princesa Subterranean River

More popularly known as Palawan Underground River, the Puerto Princesa Subterranean River (aka as St. Paul Subterranean River) is the major attraction in the Puerto Princesa Subterranean National Park in the island province of Palawan. The province lies between the South China Sea and Sulu Sea. The national park features a limestone karst mountain backdrop with an 8.2 km navigable underground river that winds through a cave before flowing directly into the South China Sea. The cave has major stalactite and stalagmite formations and a number of large chambers. Palawan Underground River is the longest navigable underground river in the world. It was incribed as a UNESCO World Heritage Site in 1999.

Chocolate Hills

The Chocolate Hills in the island of Bohol is a geological formation like no other. It is a rolling terrain of haycock hills spread over an area of more than 50 sq km (20 sq mi). There are about 1,776 hills measuring from 30-50 m (98-160 ft) high with the highest reaching 120 m (390 ft). The cone-shaped, almost symmetrical limestone mounds are covered in green grass that turns brown during summer, hence the name.

Hypotheses on how the Chocolate Hills were formed include: the uplift of the seafloor or uplift of coral deposits plus the action of rain water and erosion, and the hills were once coral reefs that erupted from the sea in a massive geological shift with the wind and rainwater putting on the finishing touches over thousands of years. Another theory says that they were once limestone deposits under the sea, uplifted by the movement of plates and molded by wind and rainwater erosion.