Akiyoshido Cave and Akiyoshidai: a guide to Japan’s great karst

In the hills of central Yamaguchi, Akiyoshidai is Japan’s largest karst plateau, and beneath it lies Akiyoshido, one of the biggest limestone caves in the country. Together they make a superb half day, and a refreshing escape from the summer heat.

How the karst was made

Around 350 million years ago, a coral reef grew in a warm sea near the equator. Over millions of years it turned to limestone, drifted north and was pushed up into hills. Rain, slightly acidic, slowly dissolved the stone, leaving pillars and sinkholes on the surface and carving a huge network of caves below.

Akiyoshido Cave

The main entrance is at the foot of a tall cliff, where a cold, clear blue river flows out of the mountain. From here, a paved and lit walkway of about 1 km leads through the cave.

• Hyakumaizara: “a hundred plates”, a cascade of shallow rimstone pools like terraced rice fields.
• The Blue Ceiling: a vast hall with a high, smooth roof.
• The Golden Pillar: a towering column of golden-brown flowstone about 15 metres tall, the cave’s most famous formation.
• The Umbrella Rocks: formations that look like stacked umbrellas.

The cave stays at around 17°C all year. At the far end, an elevator takes you up to the plateau, so you can go in one entrance and come out at the top.

The plateau

From the Karst Observation Deck, walking paths lead across the grassland among the limestone pillars and sinkholes. In spring and summer it is green; in autumn, the pampas grass turns silver and gold. Each February, local people set the grass on fire in yamayaki, a controlled burn that keeps the plateau open grassland and lights up the hills in a dramatic blaze.

Getting there

• By bus: buses run from Shin-Yamaguchi Station, about 45 minutes, and from Yamaguchi city. They are not very frequent, so check the times.
• By car: about 40 minutes from Shin-Yamaguchi, and about an hour from Hagi.
• On a tour: day tours from Fukuoka often combine the cave with Motonosumi Shrine.

Tips

• Allow about an hour for the cave and an hour or two for the plateau.
• Wear shoes with a good grip, and bring a light layer.
• Akiyoshidai Safari Land, a drive-through safari park, is nearby if you are travelling with children.
• Continue north to Hagi, or read our four-day itinerary.