Dong Hoi is a small city that packs a punch. Dong Hoi is developing quickly in comparison to the ruins that occupy much of it’s forests. The most recommended place to see in Dong Hoi is the Phong Nha Ke Bang national park. The park is filled with the oldest karst mountains in Asia, which may sound like a German man coughing, but it is actually a very cool looking rock formation. The rocks are filled with wondrous caves. Just a short drive away are the Quang Phu Cat Hills. These will shock you, as even Sahara-looking desert landscapes exist in Vietnam.