We recommend 2 diffirent caves or place for a single day trip: Phong Nha cave and Paradise cave, Paradise cave or Dark cave, Botanical Garden is a quick stop before entering the national park's core zone. Phong Nha cave is not only a natural legacy of the world. It also stands as a relic system of the historic Ho Chi Minh trail which, during the US war, served as a secret hiding place for floating bridges that were only brought out at night to avoid targeted bombings. These bridges were key components in the supply chain from the north to the south by allowing supply trucks to cross the rivers. It also once served as a hospital, with weapons installed at the entrance. Once its location was discovered, it was heavily bombed, resulting in the external scarring you see today. This area has now become the first section of the ever popular Ho Chi Minh trail, as it showcases a lush, mountainous landscape. Paradise cave is the longest dry cave in Asia (located in Phong Nha – Ke bang National Park’s core zone. With naturally primitive features, Paradise Cave looks like a landscape painting; making it a natural wonder that many have enjoyed since its opening in 2010. According to spelunkers (cave explorers), the deeper one journeys into the cave, the more one feels the wells of heavenly clarity all around. The cave height can reach to 72 m and up to 150 m wide. There are a series of white crystal stalactites (limestone deposits) resembling natural pillars and many other spectacular formations. Dark cave is an adventurous and action-packed experience. Visiting this cave includes harnessed zip lining over a turquoise river, swimming into the mouth of the cave (lifejackets included), walking through the dark with only the head torch on your mining helmet to illuminate the way, having a mud fight in the buoyant mud baths deep in the cave, washing clean with a swim in the lake inside the cave, then kayaking back across the river to test your strength on the hanging obstacle course and open ziplines.