Karatsu Sea Cave Kayaking — Through the Basalt Cliffs

**Cave exploration:** The deepest accessible cave (Cave #4) extends 45m into the cliff and narrows to kayak-width at the far end — claustrophobic but extraordinary. The guide carries a waterproof torch; bring a camera in a dry bag. **Sunset tour (June–September):** The 16:00 tour returns to harbor at sunset over the Genkai Sea — the sea caves in late afternoon light, with orange reflecting off the water inside the basalt chambers, creates conditions impossible to photograph accurately but unforgettable in memory.