N0-6 Tonkararin Tunnel Structure
The “Tonkararin Tunnel Structure” is a mysterious tunnel structure located on the east side of the plateau connected to the Etafunayama Tumulus.  The edge of the tunnel is located slightly below Sugahara Shrine on the Sugahara plateau. From there, ground fissures called culverts and gullies connect all the way to a culvert of arranged stones commonly known as “Tantan Otoshi.” The tunnel is 445.1 meters long. It is still unclear when it was constructed, why and by whom, and historical resources and local legends give no hints. It is possible to actually pass through the tunnel and view its structure and the differences in sizes such as the ground fissures with ceiling stones, stone stairs, and culverts only passable by crawling. Please wear loose-fitting clothing that you can get dirty in, and bring work gloves and flashlights, and come try to solve the mystery while enjoying the spirit of exploration.
  • 商工観光課
  • 熊本県玉名郡和水町江田3886 0968-86-5725
  • 三加和支所
  • 熊本県玉名郡和水町板楠70 0968-34-3111