Slowly becoming one of the world’s most famous underground destinations (literally), the Phong Nha-Ke Bang National Park area is a guaranteed fascinating visit. Housing the largest cave complexes in the world, visitors can delve into the subterranean mysteries of this vastly undiscovered region with endless karst formations, caves, grottoes and much more. There are plenty of opportunities for spelunking, but also hiking, kayaking, cycling, exploring local villages and much more.