As North Korea shows off its nuclear missiles and tanks, some in nearby Japan are preparing for the worst. A growing number of Japanese people are building bunkers that could theoretically help protect them from nuclear warfare, Reuters reports.

A Reuters photographer recently went inside a model bunker created by Shelter Co., an Osaka-based company that makes underground nuclear shelters for homes in Japan. The shelter is located inside the home of the company’s CEO, Seiichiro Nishimoto.

Take a look inside.