Recently hailed as one of the New 7 Wonders of Nature, the Underground River located inside a national park, is also a UNESCO World Heritage Site. It is approximately 2 hours north of the city proper. On your way to the area, be amazed at the splendid top view  of Ulugan Bay, and marvel at the karst limestone mountains and elephant cave.

From Sabang wharf, a motorized boat will take you to the entrance of the national park for 20 minutes. A boardwalk  winding through dense jungle thickets will lead you to the mouth of the cave. There a boatman who will also serve as your guide will show you the wonders waiting for you inside.