Wakayama · Kada / Kitan StraitNo.919★★Open in map →

Tomogashima Islands

— Meiji fort ruins on an island off Kada

historyOff the trail — and worth it

Four uninhabited islands in the strait between Wakayama and Awaji, where an abandoned Meiji-era coastal fortress is being taken apart by moss and roots. Twenty minutes by boat from Kada, and a full day once you are there.

FromWakayama-shi Station
~1 h 20 minNankai train, then a 20-min ferry
Get off atKada Station (Nankai Kada Line)
From there
Tomogashima Islands

Directions ↗

The sweet spot

This is a known destination, well signposted by the prefecture, and summer weekends bring a queue at the Kada pier. What keeps it quiet is the logistics: it is an hour and more from central Wakayama, the boat runs only a few times a day, and once the last sailing leaves there is nothing on the island to stay for.

Where it is

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What to look for

Tomogashima LighthouseOzizo / Public domain

Battery No. 3the largest and best-preserved of the ruins, with brick tunnels and gun pits you can walk into
Battery No. 1a position on the high ground near the island's western end, with an open view over the strait
Tomogashima Lighthousethe white nineteenth-century tower on the western tip, the island's landmark from the water
Battery No. 2blown up after the war and left where it fell, its collapsed walls sliding towards the shore

How to actually get there

Wakayama-shi Station → Kada Station (Nankai Kada Line, about 30 minutes).
Kada Station → Kada Port (walk about 20 minutes through the village).
Kada Port → Okinoshima (boat, about 20 minutes); confirm your return sailing on landing.
Walk the island circuit past the batteries and the lighthouse, then return to the pier.

Nankai Kada Line to the end of the branch: From Wakayama-shi Station take the Nankai Kada Line west to its terminus at Kada, roughly thirty minutes on a two-car local along a short branch line. Kada is the westernmost station in Wakayama Prefecture and the original wooden station building is still in use. Some services run as the decorated Medetai Densha tourist trains.
The same boat, then the same branch line: There is one way off the island and it is the boat you arrived on, so treat the last sailing as the hard deadline of the day. Back at Kada Port, allow twenty minutes on foot to the station, then the Kada Line to Wakayama-shi for connections towards Osaka. Trains thin out in the evening, so check the board at Kada before you leave for the pier in the morning.

Directions from my location (Google Maps) ↗

About the place

Tomogashima is not one island but four, sitting in the Kitan Strait between the tip of Wakayama and the island of Awaji, within Setonaikai National Park. Nobody lives on them. The one visitors land on is Okinoshima, and it carries the remains of five gun batteries built to close the sea approach to Osaka Bay. What survives is red brick: arched magazines, sunken gun pits, stairways and tunnels, all of it slowly going green under moss and root. The comparison to the floating castle in Studio Ghibli's Castle in the Sky is the one everybody reaches for, and it is close enough to be useful. Trails link the batteries across the wooded ridge, with lookouts over the strait.

How to enjoy it

The crossing takes about twenty minutes and sailings are few, so the day is built around the boat rather than the island: fix your return departure before you walk off the pier. A circuit of the batteries and the lighthouse fills the middle of the day comfortably, and the ruins photograph best under flat cloud, which keeps the brick and moss from blowing out. Wear shoes you can climb in.

Background & history

The batteries belong to the Yura Fortress, the ring of coastal defences the army built in the Meiji era to guard the sea entrance to Osaka Bay. Gun positions went up across Okinoshima and on the neighbouring islet of Torashima, and the strait was closed to civilian traffic and kept off published maps. During the Second World War the islands were taken over again as a military site. The lighthouse on the western end is older than any of it: a Western-style tower from the nineteenth century, among the first of its kind in Japan, standing almost exactly on the meridian that sets Japan Standard Time.

Before you go

Cash: The round-trip boat fare is 2,200 yen for adults and 1,100 yen for children at the time of checking. The island is set up for walking, picnicking and camping rather than shopping, so bring water and food with you. Carry cash; do not count on card payment at the pier.
Good to know: Sailings do not run every day — the prefecture's tourism listing shows a weekday closure pattern that differs between the warmer and colder months — and rough weather cancels the boat outright, sometimes after you have already crossed. Paths are unlit, uneven and steep in places, and the tunnels inside the batteries are dark enough to want a torch.
Another way: From Osaka, take the Nankai Main Line from Namba to Wakayama-shi and change there for the Kada Line; from JR Wakayama Station, transfer to Wakayama-shi first. A taxi from Kada Station to the port shortens the walk.
After you get off: From Kada Station it is about twenty minutes on foot through the fishing village to Kada Port, where the Tomogashima boat leaves; the crossing lands at the pier on the eastern side of Okinoshima.