Phong Nha-Ke Bang National Park boasts many attractions, but none is so popular as its caves. The Phong Nha Caves are made up of hundreds of cave systems, many of which are large enough to hold entire city blocks. The biggest, and most notable, is Hang Son Doong. A gateway to the caves is Son Trach, a growing village that is home to several transport links throughout Vietnam, local restaurants and meeting points for guided tours to the caves.