Keya no Oto — the “Great Gate of Keya” — is a sea cave at the far western tip of the Itoshima peninsula. The headland is a mass of columnar basalt: lava that cooled into tight bundles of six-sided pillars, now a 64-metre cliff with a cave about 10 metres wide and some 90 metres deep worn into its foot by the waves of the Genkai Sea.
It is counted among Japan’s three great basalt caves and was designated a National Natural Monument in 1966. You cannot see the cave mouth from land, which is why the small sightseeing boats from Keya fishing port are so popular: in calm conditions the skipper takes the bow right inside.
Top things to do: Keya no Oto Sea Cave
Take the sightseeing boat
Boats leave from Keya fishing port and take around 25 minutes for the round trip, running along the cliffs to the cave mouth and, sea permitting, into it. The boat usually operates from about mid-March to the end of November and is cancelled in wind or swell — which is common, so treat it as a bonus rather than a certainty. Fares are modest; check the current price and the day’s sailings at the port.
Walk the “Totoro forest” to the viewpoint
From the car park near the port a short trail leads through a tunnel of evergreen trees — nicknamed the Totoro forest for its resemblance to the film — up to an observation deck on top of the headland. It takes 10–15 minutes each way and gives you the cliffs and the open sea even when the boats are not running.
Swim or stroll at Keya beach
Just around the corner, Keya beach is one of the best swimming beaches in Itoshima: a sheltered arc of white sand with summer beach houses.
Climb Tateishi-yama for the view from above
The rocky hill behind the beach is Tateishi-yama, about an hour’s climb, with a bird’s-eye view of the whole cape.
How to get there
- By car: about 25–30 minutes from Chikuzen-Maebaru Station and around an hour from central Fukuoka. There is parking near the fishing port and the trailhead.
- By bus: buses run from Chikuzen-Maebaru Station to Keya (about 30–40 minutes). Services are limited, so check the timetable in both directions.
- By tour: several day tours include the Totoro forest walk, and one private tour includes the boat.
Insider tips
- Call or check on the day whether the boat is sailing — the sea can be too rough even under a blue sky.
- The boats are small and open. Expect spray, and keep cameras and phones on a strap.
- The trail to the viewpoint is easy but uneven; wear proper shoes rather than beach sandals.
- In winter, when the boats stop, combine Keya with the oyster huts at nearby Kishi port instead.
Best tours & tickets: Keya no Oto Sea Cave
These top-rated experiences are the easiest way to see Keya no Oto Sea Cave and the rest of Itoshima:
Private tour from US$1013 per group Fukuoka: Itoshima Private Shore Excursion, Lunch & Sea Cave
A premium private day with pickup in Fukuoka: Shiraito Falls, the boat to the Keya no Oto sea cave and a lunch of fresh local ingredients. The price is per group of up to two, and the cave boat depends on sea conditions.
- Shiraito Falls
- A boat trip to the Keya no Oto sea cave
- Lunch made with fresh local ingredients
Bus day trip from US$50 Coastal Escape: Itoshima Peninsula One Day Tour from Kyushu
A guided day from Fukuoka that pairs Itoshima’s two big hill sights — Shiraito Falls and Sennyoji Daihioin temple — with the Totoro forest trail and the coastline. A good choice in autumn, when the temple’s maple is at its best.
- Shiraito Falls
- Sennyoji Daihioin temple
- The Totoro forest trail
Bus day trip from US$63 Fukuoka: Itoshima Day Trip | Daily Guaranteed Departure
A full-day coach tour advertised with a guaranteed daily departure — useful if your dates are fixed. It visits Shiraito Falls, a forest café, the Totoro forest and several coastal spots, with fresh seafood and a multilingual guide.
- Shiraito Falls and a forest café
- The Totoro forest and coastal viewpoints
- Fresh seafood and a multilingual guide
