Hisa Kinzoku Kogyo Former Air Raid Shelter

Hisa Kinzoku Kogyo Former Air Raid Shelter: A Concrete Box behind the Mound

The Hisa Kinzoku Kogyo Former Air Raid Shelter (久金属工業旧防空壕, Hisa Kinzoku Kōgyō Kyū Bōkūgō) is a small reinforced-concrete structure behind the landscaped mound inside the main gate of a bottle-cap maker's head-office factory in Kitatsumori, Nishinari Ward, Osaka City, built around 1934, altered in 1967 and registered as a Registered Tangible Cultural Property on February 4, 2021.

It is a single story with a flat roof and a building area of 9.4 square meters. The north side backs onto the mound, and the south face has lattice windows placed symmetrically.

Despite the name, the Agency for Cultural Affairs is careful to say only that the building is traditionally held to have been an air raid shelter. No record of its wartime use has been published.

Why the Former Air Raid Shelter Was Registered

According to the Agency, the Hisa Kinzoku Kogyo Former Air Raid Shelter was turned into a toilet after the war, and the underground chamber appears to have been converted into a septic tank. Even so, the Agency judges that the exterior keeps its original appearance. It was registered for contributing to the historic landscape.

The date is uncertain. The Agency gives about 1934, while the company website gives about 1940. Neither source explains how the building relates to the period when it served as a shelter. This article follows the Agency.

What to Look For: A Faux-Wood Vent in the Mound

The company says the space below ground was large enough to shelter the staff. As a trace of that, a ventilation shaft rises from the roof through the mound, its surface finished in giboku, a plasterer's technique of modeling concrete or mortar to look like tree bark.

The symmetrical lattice windows on the south face give the little concrete box a composed front. It has passed from wartime refuge to postwar lavatory with its exterior hardly changed.

Visiting the Former Air Raid Shelter

The Hisa Kinzoku Kogyo Former Air Raid Shelter is hidden by the mound from the main gate and cannot be seen from the street. It lies inside the factory grounds and can be seen only when an open-house tour includes it.

If you get close, look for the bark-textured vent poking up through the mound. The chamber below is believed to have become a septic tank and cannot be entered.