Towards the southern end of Akiyoshidai is the  Akiyoshidō cave, named by Emperor Hirohito on May 30, 1926, when he was still crown prince. This spacious cave is up to 100 meters wide and has 8.79 kilometers of passages, making it one of the longest in Japan after Akkadō cave, and one of the longest in Asia.
The Akiyoshidō cave, located at the southern end of Akiyoshidai, was named by Emperor Hirohito on May 30, 1926, when he was still a crown prince. This expansive cave boasts passages that stretch up to 8.79 kilometers in length, ranking among the longest in Japan after Akkadō cave and Asia as a whole.