Longquandong is one of the three major bell milk caves in Japan and is a national natural monument. The total length is more than 5,000 meters and is still under investigation. It takes about 30 minutes to visit the open part. Longquandong address Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-Iwazuma-I In addition, there are cave stone curtains, stalactites, cave corals, etc. There are precious rabbit ear bats living in the cave.