WAKAYAMA -- Once the heavily fortified guardians of Osaka Bay, the now uninhabited Tomogashima Islands are drawing young visitors for their resemblance to the fictional world of the animated film "Castle in the Sky."

Situated at the southern tip of Osaka Bay, the Tomogashima Islands in the city of Wakayama were military installations from the Meiji era (1868-1912) until the end of World War II. The islands consist of four islets -- Okinoshima, Jinoshima, Torajima and Kamijima -- strung between Wakayama Prefecture and Awaji Island in Hyogo Prefecture.

There were five artillery batteries built on the largest, Okinoshima, during the Meiji era. The primary one, battery No. 3, was completed in 1892, and remnants like gun emplacements, ammunition depots and soldiers' quarters known as "empeibu" can still be seen. The brick structures are shrouded in dense foliage, and stepping into the soldiers' quarters where light scarcely penetrates, the darkness and silence evoke the atmosphere of that time.

It has long been a popular hiking destination for its scenery. However, the battery ruins' contrast of red-brown bricks against lush greenery has drawn young visitors who discovered the islands through social media posts evoking parallels with the world of the famous Studio Ghibli film "Castle in the Sky." The islands, off-limits to the public until the end of the war, now take visitors back to a time 80 years ago.

(Japanese original by Yuichi Nakagawa, Osaka Photo and Video Department)