At 8.2km, the Puerto Princesa Subterranean River stands as the longest river of its kind across the globe. Surrounded by gorgeous limestone karst and a completely diverse, mountain-to-sea ecosystem, it is no surprise that the river would be named one of the new seven wonders of nature! However, there is still more to love about this enticing destination. For instance, the river actually runs straight into the sea, meaning the lower half is impacted by the rising and falling of the ocean tides. It also has a second floor that is full of small, rushing waterfalls. Located just north of Puerto Princesa, Palawan and nestled into a UNESCO listed national park, it is super easy to book a day trip to travel along the Philippines’ famous underground river. So, on that note, be prepared to witness some of the most astounding sights the world has to offer!