Rashōmon

Rashōmon is a limestone cave in Niimi formed through centuries of natural erosion and dissolution processes. It features dramatic natural arch formations that rise approximately 40 meters high.

The cave was discovered during the Edo Period when a hunter pursuing a raccoon dog accidentally found this geological formation in the mountains. This chance discovery revealed an underground landscape that has intrigued people since.

The cave served as a filming location for Japanese productions, including an adaptation of the mystery novel Village of Eight Graves by writer Yokomizo Seishi. Visitors can explore the spaces that appeared in these films.

The cave entrance requires careful navigation down slippery paths from the main parking area. Informational signs along the way help guide visitors safely to the site.

In early July, the cave environment supports populations of Hotaria parvula fireflies that illuminate the natural surroundings with their bioluminescent glow. These glowing insects create a magical display within the underground landscape.