Ha long bay caves.

At Ha Long Bay, it is home of many spectacular caves with unique geology, aesthetics, and archaeology values. Although the trek into the cave is tiring due to the stairs and humidity, but once you are in, you will be truly amazed by the natural structure of the caves various stalactites and stalagmites hanging from the ceiling. Furthermore, the stone artifacts date back to several years ago so you can learn interesting historical information from the tour guide.