This one is interesting to me for two main reasons: one is that it's a unique WW2 historic attraction in this area and two is the connection to Korean slavery.

For some background, The Matsushiro Underground Imperial Headquarters was a massive bunker complex built during World War II in Japan. It was designed as a secret refuge for the government in case of an Allied invasion, with tunnels under several mountains housing various facilities. Constructed with the "help" of Korean forced laborers, the project was never completed due to Japan's surrender.

A lot of unfortunate events happened during the war times and I believe it's important to remember these kinds of place and stories to honor those who endured. For me, I had mixed feelings about the place in that I enjoyed walking through the underground complex because it's an engineering feat and it's impressive to see the lengths the military went for war to construct something like this. However, I also had a sombre feeling the experience because of the unfortunate slavery that built this place.

For these reasons, I do recommend a visit! A lot of people will visit Hiroshima for WW2 history but you can see a very interesting connection to those events right in the mountains. Literally.