Rolling green grassland dotted with grey limestone rocks on the Akiyoshidai plateau

Karst & cave

Akiyoshidai & Akiyoshido Cave

Akiyoshidai is Japan’s largest karst plateau, a sweep of grassy hills covered in thousands of grey-white limestone pillars, formed from an ancient coral reef. Deep beneath it lies Akiyoshido, one of the largest limestone caves in Japan, with a walkway of about 1 km through vast halls, rimstone pools and towering formations.

Why visit

About 350 million years ago, this area was a coral reef in a warm sea. Over time, the reef turned to limestone, was lifted up into the hills, and was slowly dissolved by rain, leaving the strange landscape of rocks and sinkholes on the plateau and the great cave below. Together they make one of the most unusual natural sights in western Japan, and an easy half day from Yamaguchi city.

Akiyoshido Cave

  • The entrance: the main entrance is a huge opening at the foot of a cliff, where a clear blue stream flows out of the mountain.
  • Hyakumaizara: “a hundred plates”, a terraced staircase of shallow rimstone pools.
  • The Golden Pillar: a towering column of golden flowstone about 15 metres high.
  • The Blue Ceiling: a huge chamber whose high roof seems to glow in the light.

The walkway is paved and lit, and an elevator at the far end connects the cave to the plateau above, so you can walk through and come out on top. Read our guide to Akiyoshido Cave and Akiyoshidai.

Limestone rocks on the grass of Akiyoshidai with the observation deck behind
Limestone pillars on the plateau near the Akiyoshidai observation deck.

The plateau

From the Karst Observation Deck, paths lead out across the grassland among the rocks and sinkholes. The views are wide and open, especially in autumn, when the pampas grass turns silver and gold. Each February, the grass is burned off in a spectacular controlled fire called yamayaki.

Tips

  • The cave stays at around 17°C all year: cool in summer, mild in winter.
  • Shoes with a good grip help on the wet paths.
  • Buses run from Shin-Yamaguchi Station and from Yamaguchi city, but they are not frequent.
  • Combine the cave with Hagi, about an hour north, or with Motonosumi Shrine on a day tour.
Share this

Book ahead

Nearby

Also worth seeing

The large red torii at the entrance to Motonosumi Shrine, decorated with white foxes Shrine

Motonosumi Shrine

123 red torii above the sea

A line of 123 red torii gates winding down a green clifftop to the Sea of Japan, with an offering box set high on a gate that you try to throw a coin into.

A quiet lane between white earthen walls and stone walls in the samurai district of Hagi Castle town

Hagi

Samurai lanes and Hagi ware

The old castle town of the Mori lords on the Sea of Japan, with samurai houses, earthen walls, the school of Yoshida Shoin and the famous Hagi ware pottery.

The Kanmon Strait and the Kanmon Bridge seen from the waterfront near Karato Market in Shimonoseki City

Shimonoseki

Fugu, a fish market and the strait

The port city at the western tip of Honshu, famous for fugu, Karato fish market and its sushi stalls, Akama Shrine and the walk under the sea to Kyushu.