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Well designed real estate in Tokyo, Japan.

Castle in the Sky – Wakayama Tomogashima Island Japan

To defend the entrance to Osaka Bay, military facilities such as artillery batteries had been built on Tomogashima Island in Kada, Wakayama Prefecture, since the Meiji period (1868-1912).

The facility was destroyed after the war, but the remnants of the time remain as they were, and the way the brick-made building grows with plants and trees seems to be a reproduction of the castle in the sky, Laputa and the dungeon of Dragon Quest.

If you land on Tomogashima Island, you will remember your childhood excitement.

What’s Tomogashima?

Tomogashima is an island located at the entrance of Osaka Bay between Wakayama Prefecture and Awaji Island.

It used to be crowded as a sightseeing spot, but now it is an uninhabited island.

4 ships a day from Kada Port. In the season, 6 ships are available. It seems that you can camp there, but it’s an uninhabited island with few facilities, so don’t miss your return ship.


Ruins like an ancient city

5 battery ruins remain on Tomogashima Island, the largest of which is the 3rd Battery Ruins in the center of the island.

It’s the highest place on the island, so you have to climb the mountain path a little.

If you go through the tunnel covered with brick trees, you will arrive at the ruins as if you had slipped back in time.

Because the walls are covered with trees, the old walls look older than they really are, as if they were the remains of an ancient city.

It’s like getting lost in an ancient site you’ve only seen in anime or RPG games.

The inside of the building is not particularly well maintained and you can go in and out freely. However, it is not very clean because there is water inside.

If you go out from the exit at the end of the dark passage, you will see the remains of the pedestal of the battery. It was probably equipped with anti-aircraft and anti-ship guns.

However, this gun battery was never used and the war ended.

Today, the pedestal of this battery is filled with water, like a garden pond.


Survival Game Equipment & Clothing


Let’s explore the pitch-dark path!

If you’ve come all the way here, take a flashlight with you and explore the dark aisles.

But it’s really dark and home flashlights don’t shine all the way, so you should bring a powerful outdoor light.

There’re stairs down to the basement, and when I searched, there was a room that looked like an ammunition depot, and it really looked like an underground labyrinth.

Unfortunately, there’re no weapons left or treasure boxes from those days, but if you look only at military facilities, there might be a secret hidden room.

The 2nd Battery Ruins

The 2nd Battery Ruins is the highlight of Tomogashima as well as the 3rd Battery Ruins, and it remains as if it jumped into the sea near Ikejirihama.

However, this place was bombed after the end of the war, so the gun battery remains have been destroyed.

The big chunks of blocks that were blown up and scattered are surprisingly tasty.


If you go south from the 2nd Battery Ruins, there’s the 1st Battery Ruins.

There’s a white lighthouse right next to here, so you can also see it.

This time, only a part of it was introduced, but in addition to the five battery ruins, there’re also old ruins, natural ponds, and animals such as deer and squirrels can be seen.

The ruins of the vegetated Tomogashima island seem to have been weathered by the fall of the Ghibli movie Castle Laputa. Why don’t you get lost in the world of anime and try to remember your child’s mind?

You can go to Tomogashima by ferry from Kada port.

The first ship is at 9:00 and the travel time is 30 minutes. The return ship is the last 16:30.

Information (Ferry terminal to Tomogashima)

  • Closed: Wednesdays
  • Ferry fare (round trip): 2,000 yen for adults, 1,000 yen for children
  • Website


Hotel URASHIMA – The Cave Onsen in Wakayama, Japan

Hotel URASHIMA – The Cave Onsen in Wakayama, Japan