Kiyotsu Gorge

Kiyotsu is a gorge of columnar joints - hexagonal rock columns from a cooled andesite flow - and the walls are impressive but the path along the river was closed after a fatal rockfall in 1988. What replaced it is a 750-metre inspection tunnel driven through the rock with four side openings looking out at the walls. In 2018, for the Echigo-Tsumari art triennale, the tunnel was reworked by the practice MAD Architects as a piece called Tunnel of Light: coloured lighting through the passage, a mirrored washroom in the middle, and at the end a chamber whose floor is a shallow sheet of water flanked by polished steel, so the gorge framed by the opening appears complete and inverted in the pool. That last chamber is the image that circulates. It is a short walk, mostly flat, and the tunnel is cold.

What you actually see

• Columnar walls - hexagonal andesite jointing on both sides of the gorge.
• A 750-metre tunnel - an inspection bore reopened with four side openings.
• The mirror chamber - a water floor and steel walls inverting the gorge at the end.
• An art commission - reworked in 2018 for the Echigo-Tsumari triennale.

When to go

Late October for colour in the frame; April to November otherwise. Two hours.

Honest expectations

The mirror chamber queues for photographs and the water is a few centimetres deep - boots or bare feet. The tunnel is cold in every season. Timed entry applies in busy periods. The gorge itself cannot be walked - the tunnel is the only access.

Nearby

Hoshitoge terraces are north-west; Echigo-Yuzawa is south.