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Akiyoshido Cave — Japan's Largest Limestone Cavern

Published: Jul 22, 2026

Updated: Jul 22, 2026

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Akiyoshido Cave — Japan's Largest Limestone Cavern

Akiyoshido Cave (秋芳洞) is Japan's most extensive limestone cave system, with 10.7km of surveyed passages of which 1km is open to the public along a paved, illuminated walkway following an underground river. The cave formed over 300 million years as rainwater dissolved the karst limestone plateau above (Akiyoshidai), creating cathedral-like chambers up to 35 meters high, cascading flowstone formations, and the massive 'Golden Pillar' — a 15-meter-tall stalagmite illuminated in amber light.

The main route through Akiyoshido follows the Akiyoshi River, which flows year-round at a constant 17°C, making the cave comfortably cool in summer and warmer than outside in winter. Geological formations include rimstone pools (棚田, terraced fields of mineral water), stalactites hanging like frozen waterfalls, and the 'Hundred Dishes' formation — a series of limestone plates resembling stacked dinnerware. The cave's scale is overwhelming: the entrance chamber (Seidoen, 青天井, 'Blue Sky Hall') measures 175m long, 80m wide, and 35m high. Discovered in local folklore centuries ago, Akiyoshido was scientifically surveyed in the 1920s and opened to tourism in 1926.

Essential Information

Opening Hours

8:30–17:30 (March–November), 8:30–16:30 (December–February)

Closed: Open year-round

Entrance Fee

¥1,300 (includes Akiyoshidai Plateau). Rear elevator ¥300. Adventure Course ¥1,000 extra.

Best Season

Year-round; cave's constant 17°C is refreshing in summer and warm in winter; combine with Akiyoshidai Plateau for 2-hour circuit

Visit Duration

60 minutes for main 1km route; 2 hours for cave + rear elevator to Akiyoshidai Plateau

Getting There

Access Information

Shuhocho Akiyoshi, Mine City. 40 min by bus from JR Shin-Yamaguchi Station. Entry: ¥1,300 (includes Akiyoshidai Plateau). Hours: 8:30–17:30 (Mar–Nov), 8:30–16:30 (Dec–Feb). Main route 1km, 60-min walk. Temperature inside: constant 17°C year-round.

Insider Guide

Premium

**Full experience route:** Enter via the main entrance (Cathedral Gate) and walk the 1km paved main route upstream, exiting via the rear 'Kuraki Pass' elevator (¥300) that ascends 80m inside the mountain to Akiyoshidai Plateau above. This avoids backtracking and connects cave to plateau in seamless 2-hour circuit. The plateau's karst landscape — thousands of limestone pillars emerging from grassland — creates an alien landscape worth 30-min exploration. **Golden Pillar timing:** The cave's highlight is the 15m 'Golden Pillar' stalagmite (黄金柱, kogane-bashira) formed over 500,000 years. It's illuminated with amber spotlights — most dramatic when you approach from downstream (standard direction). Pause here for 5 minutes to appreciate the scale; most tourists rush past. The pillar's color comes from iron oxide in the limestone, not actual gold. **Adventure cave route:** For experienced spelunkers, the 'Adventure Course' (冒険コース, bouken course, separate ¥1,000 fee, advance reservation) explores 300m of undeveloped passages requiring crawling, climbing, and helmets. Offered 3x daily (10:00, 12:30, 15:00), 90-min duration. Not for claustrophobes but offers thrilling contrast to the paved tourist route. Book at main ticket office. **Photography notes:** Bring fast lens or high-ISO camera — the cave is dimly lit to prevent algae growth on formations. Tripods are not allowed on main route (obstruct traffic). The most photogenic formations are 'Hundred Dishes' (30 min from entrance) and 'Golden Pillar' (50 min). Flash photography is permitted but natural light + spot illumination creates better atmosphere.

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