Quảng Bình Province in central Vietnam, is home to the famous Phong Nha cave system. The region is a national park and UNESCO World Heritage Site 500 km south of Hanoi. Phong Nha is composed of 300 caves and grottoes. This is home to the famous Son Doong – the world’s BIGGEST cave – a place so vast that it would contain a whole Manhattan city block, skyscrapers and all. But for those on a short timetable there are a lot more places that are easier to explore. Referred to as an “underground palace,” Paradise cave is actually Asia’s longest cave. It is considered a masterpiece of nature with myriads of stalactites hidden deep in the ground. It is colossal. 72m in height, 150m in width and 31 kilometres in length but most tours will only take you on a one kilometre trek. Phong Nha Cave was the first cave to be opened to the public and is reached by a boat journey up the river from Phong Nha Village. Phong Nha Cave was used for shelter and as a hospital during the Vietnam War. It’s well worth a visit, especially for the journey in the traditional Dragon Boat up the waterways and through the cave itself. This cave is almost 8000 metres long. It contains 14 grottoes and a 14,000 metre underground river. From here, the journey required a trek along a steep and steamy pathway. Dark Cave (Hang Toi) is for real adventure lovers. There are no lights in the cave, and after zip-lining across the river or traversing the jungle, you swim through the cave with your head-torch lighting the way. You then have to venture through a muddy side passage before heading back to the sunlight. Below and above ground, Vietnam is a true nature’s paradise.