Lake Ikeda — Giant Eel and Volcano Cone

Published: Jun 1, 2026

Updated: Jun 1, 2026

Lake Ikedacaldera lakeMt. Kaimongiant eelIssie

Lake Ikeda (池田湖) is a volcanic caldera lake — the largest lake in Kyushu at 15km circumference — with Mt. Kaimon (開聞岳, 924m), a perfectly conical volcano, rising from the shore. The lake is famous for two things: giant eels (up to 2 meters long, weighing 20kg) that inhabit the deep water, and persistent rumors of a lake monster called Issie (à la Loch Ness Monster).

The lakefront has rental swan boats, eel observation tanks, and flower fields (nanohana in January, sunflowers in summer).

Opening Hours

Lakefront 24 hours (free access). Swan boats and eel viewing tanks approximately 9:00–17:00.

Closed: Outdoor access always available. Boat rental and viewing facility hours vary.

Entrance Fee

Lakefront free. Swan boats ¥700/30 min. Giant eel observation tanks free. Mt. Kaimon trailhead parking ¥200.

Best Season

January for nanohana (canola flowers) along the lakeshore; summer for sunflowers; clear days any season for the best view of Mt. Kaimon's perfect cone

Visit Duration

1.5–2 hours for lake viewpoints and eel observation; add 4 hours for the Mt. Kaimon round-trip hike

Getting There

Access Information

Ikeda, Ibusuki City. 20-min drive from Ibusuki Station. Free access. Swan boats: ¥700/30 min. Giant eel tanks at Ikeda-ko Pa-ku (free viewing). Mt. Kaimon hiking: 4-hour round-trip from lake area.

Insider Guide

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**Mt. Kaimon hike:** The volcano's perfect cone shape makes it Kagoshima's 'little Fuji.' The hiking trail ascends 900m in 2.5km (one-way) — steep but well-maintained with chains on exposed sections.