Useful Information

Location: Nagomi.
(32.968237, 130.603508)
Open: no reestrictions.
Fee: free.
Classification: SubterraneaEnigmatic Cavern
Light: bring torch
Dimension: L=445m.
Guided tours: self guided
Photography: allowed
Accessibility: no
Address: Tonkararin, 3481 Segawa, Nagomi, Tamana Bezirk, Kumamoto 865-0135, Tel: +81-, Fax: +81-,
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1970s tunnels first observed.


トンカラリン (Tonkararin) is one of those underground spaces where we have absolutely no explanation for its use. It is a narrow artificial tunnel, partly with a stone wall, partly bare-earthen. The dating of this site is also unclear. The name 'ton-kara-rin' is supposed to express the reverberating sound in this cave. Others think it is derived from the Korean word Tongurami. But thats as enigmatic as the whole story, as there is no such Korean word.

The mystery around the tunnel was actually a reason why it became quite famous after it was discovered, Numerous specialists had theories about its origin. A famous Japanese novelist who was also an ancient history buff, suggested that the site might be connected to the ancient kingdom of Yamataikoku. This kingdom is as mysterious as the tunnel, it was mentioned in Chinese texts. It's location was given as "within Japan", and according to the text it was ruled by a powerful Queen named Himiko. Its more or less the Chinese/Japanese version of the King Arthur legend.

In the 1970s the archaeologists interpreted the tunnel as an ancient water course or channel from the time of the nearby Kofun tombs (5th or 6th century). more recent speculations suggest a religious use, some kind of shamanistic ritual with re-birth. There are no myths or legends about the tunnels.

To visit the tunnels you need good shoes, a lamp, and clothes to change, because you might get dirty. We also recommend a helmet and gloves, probably kneepads.